Here document
A here document (or "heredoc") is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text.
You are encouraged to solve this task according to the task description, using any language you may know.
Depending on the language being used, a here document is constructed using a command followed by "<<" (or some other symbol) followed by a token string.
The text block will then start on the next line, and will be followed by the chosen token at the beginning of the following line, which is used to mark the end of the text block.
- Task
Demonstrate the use of here documents within the language.
- Related task
11l
11l does not have here-docs. It does however have raw strings which can be used similarly. <lang 11l>print(‘ here
doc
’)</lang>
8th
Multiline strings are simply parsed using "quote", which parses first a character to use as a separator, and scans until that character is found: <lang forth> quote * Hi
there
- .
</lang>
- Output:
Hi there
Ada
Ada has neither heredocs nor multiline strings. A workaround is to use containers of strings:
<lang Ada>with Ada.Containers.Indefinite_Vectors, Ada.Text_IO;
procedure Here_Doc is
package String_Vec is new Ada.Containers.Indefinite_Vectors
(Index_Type => Positive,
Element_Type => String);
use type String_Vec.Vector;
Document: String_Vec.Vector := String_Vec.Empty_Vector & "This is a vector of strings with the following properties:" & " - indention is preserved, and" & " - a quotation mark '""' must be ""escaped"" by a double-quote '""""'.";
begin
Document := Document & "Have fun!";
for I in Document.First_Index .. Document.Last_Index loop
Ada.Text_IO.Put_Line(Document.Element(I));
end loop;
end Here_Doc;</lang>
- Output:
This is a vector of strings with the following properties: - indention is preserved, and - a quotation mark '"' must be "escaped" by a double-quote '""'. Have fun!
ALGOL 68
Algol 68 does not have a "heredoc" feature. It can be crudely achieved using an array of strings:
<lang algol68>#!/usr/local/bin/a68g --script #
[]STRING help = ( "Usage: thingy [OPTIONS]", " -h Display this usage message", " -H hostname Hostname to connect to" );
printf(($gl$,help,$l$));
printf(($gl$, "The river was deep but I swam it, Janet.", "The future is ours so let's plan it, Janet.", "So please don't tell me to can it, Janet.", "I've one thing to say and that's ...", "Dammit. Janet, I love you." )) </lang>
- Output:
Usage: thingy [OPTIONS]
-h Display this usage message
-H hostname Hostname to connect to
The river was deep but I swam it, Janet.
The future is ours so let's plan it, Janet.
So please don't tell me to can it, Janet.
I've one thing to say and that's ...
Dammit. Janet, I love you.
ARM Assembly
<lang ARM Assembly> /* ARM assembly Raspberry PI */ /* program heredoc.s */
/* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ WRITE, 4 @ Linux syscall
.equ BUFFERSIZE, 100
/* Initialized data */ .data szMessString: .asciz "String :
ABCD
EFGH TAB \n"
szCarriageReturn: .asciz "\n"
/* UnInitialized data */ .bss
/* code section */ .text .global main main:
ldr r0,iAdrszMessString @ display message bl affichageMess
100: @ standard end of the program
mov r0, #0 @ return code mov r7, #EXIT @ request to exit program svc 0 @ perform system call
iAdrszMessString: .int szMessString iAdrszCarriageReturn: .int szCarriageReturn
/******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess:
push {r0,r1,r2,r7,lr} @ save registers
mov r2,#0 @ counter length */
1: @ loop length calculation
ldrb r1,[r0,r2] @ read octet start position + index
cmp r1,#0 @ if 0 its over
addne r2,r2,#1 @ else add 1 in the length
bne 1b @ and loop
@ so here r2 contains the length of the message
mov r1,r0 @ address message in r1
mov r0,#STDOUT @ code to write to the standard output Linux
mov r7, #WRITE @ code call system "write"
svc #0 @ call system
pop {r0,r1,r2,r7,lr} @ restaur registers
bx lr @ return
</lang>
AutoHotkey
AutoHotkey uses "continuation sections" for literal text:
<lang AutoHotkey>MyVar = "This is the text inside MyVar" MyVariable = (
Note that whitespace is preserved As well as newlines. The LTrim option can be present to remove left whitespace. Variable references such as %MyVar% are expanded.
) MsgBox % MyVariable</lang>
AWK
The awk extraction and reporting language does not provide any markup facility for embedding here documents within an awk script. The awk utility is really a helper tool often used from within the Unix shell. The Unix shell in which awk scripts are usually embedded does support the use of here documents, and the way that here documents are used within the shell make them ideal for passing to awk as is, without the need for an additional facility in awk.
Bracmat
Strings in Bracmat can continue over many lines. They start and end with a quote. Quotes in the text must be escaped with a reverse solidus, like the reverse solidus itself.
<lang bracmat>( {Multiline string:} " Second line Third line \"quoted\" A backslash: \\ ":?stringA & out$("Multiline string:") & out$(!stringA) )</lang> Output:
Multiline string: Second line Third line "quoted" A backslash: \
C
The program speaks for itself ;) <lang C>
- include <stdio.h>
int main() {
puts(
"The Heredoc task was marked not implementable in C.\n"
"Frankly the person who did so seems to have little idea\n"
"of what C is capable of.\n"
"After all, what would one call this multiline string?\n"
"I may be old, but do not forget that it all started with me.\n"
"Ever enigmatic...\n\n"
"C "
);
return 0;
} </lang> Output:
The Heredoc task was marked not implementable in C. Frankly the person who did so seems to have little idea of what C is capable of. After all, what would one call this multiline string? I may be old, but do not forget that it all started with me. Ever enigmatic... C
C#
C# has a string literal call which is used for heredoc functionality
<lang C sharp>using System;
class Program {
static void Main(string[] args)
{
Console.Write(@"
multiline strings are easy to put together in C#");
}
}</lang>
C++
C++11 raw string literals are similar to heredocs, except there is no newline after the opening token or before the ending token (unless you actually want newlines there).
<lang cpp>#include <iostream> // Only for cout to demonstrate
int main() {
std::cout <<
R"EOF( A raw string begins with R, then a double-quote ("), then an optional identifier (here I've used "EOF"), then an opening parenthesis ('('). If you use an identifier, it cannot be longer than 16 characters, and it cannot contain a space, either opening or closing parentheses, a backslash, a tab, a vertical tab, a form feed, or a newline.
It ends with a closing parenthesis (')'), the identifer (if you used one),
and a double-quote.
All characters are okay in a raw string, no escape sequences are necessary
or recognized, and all whitespace is preserved. )EOF"; }</lang>
Clojure
There are no heredocs built in, but Clojure Strings themselves are multiline and whitespace/indentation is preserved. If your text has many characters that have to be escaped, it may make more sense to store it as a resource file and read it in.
For more information on the possibility of supporting a tripled-quoted syntax, see: alternate string quote syntaxes.
CoffeeScript
CoffeeScript borrows the triple-quoted string syntax from Python. Note that these strings strip leading whitespace in CoffeeScript, to allow you to neatly align the heredoc string.
<lang coffeescript>myDoc =
Single-quoted heredocs allows no '#{foo}' interpolation.
This behavior is similar to single-quoted strings.
doc2 = """
However, double-quoted heredocs *do* allow these.
See it in action:
Content: "#{myDoc}"
"""
console.log doc2</lang>
- Output:
However, double-quoted heredocs *do* allow these.
See it in action:
Content: "Single-quoted heredocs allows no '#{foo}' interpolation.
This behavior is similar to single-quoted strings."
Note how the extra indentation in the third line of doc2 is preserved.
Common Lisp
cl-heredoc provide read-macro for heredoc:
<lang lisp>;; load cl-heredoc with QuickLisp (ql:quickload 'cl-heredoc)
- use #>xxx>yyyyyyyy!xxx as read-macro for heredoc
(set-dispatch-macro-character #\# #\> #'cl-heredoc:read-heredoc)
- example
(format t "~A~%" #>eof1>Write whatever (you) "want",
no matter how many lines or what characters until
the magic end sequence has been reached!eof1) </lang>
- Output:
Write whatever (you) "want", no matter how many lines or what characters until the magic end sequence has been reached! NIL
Note: NIL is the return value of function format when first argument is t
D
<lang d>import std.stdio, std.string;
void main() {
// Delimited strings: a 'q' followed by double quotes and an // opening and closing delimiter of choice:
q"[a string that you "don't" have to escape]" .writeln;
// If the delimiter is an identifier, the identifier must be // immediately followed by a newline, and the matching delimiter // is the same identifier starting at the beginning of the line:
q"EOS This is a multi-line heredoc string
EOS".outdent.writeln;
// std.string.outdent is used to remove the four spaces indent.
}</lang>
- Output:
a string that you "don't" have to escape This is a multi-line heredoc string
DWScript
Double-quotes (") denote a multi-line string, to include a double-quote in such a string, you need to double it. <lang delphi>PrintLn("This is a multiline ""string"" sample");</lang>
- Output:
This is a multiline "string" sample
EchoLisp
The delimiters are #<< .... >># for a here-doc string, which may include any special character: double quotes, new line, etc. and is read 'as is', i.e does not recognize escape sequences.
(string-delimiter "") (writeln #<< A noir, E blanc, I rouge, U vert, O bleu : voyelles, Je dirai quelque jour vos naissances latentes : A, noir corset velu des mouches éclatantes Qui bombinent autour des puanteurs cruelles, Golfes d'ombre ; E, candeur des vapeurs et des tentes, Lances des glaciers fiers, rois blancs, frissons d'ombelles ; I, pourpres, sang craché, rire des lèvres belles Dans la colère ou les ivresses pénitentes ; U, cycles, vibrements divins des mers virides, Paix des pâtis semés d'animaux, paix des rides Que l'alchimie imprime aux grands fronts studieux ; O, suprême Clairon plein des strideurs étranges, Silences traversés des Mondes et des Anges : - O l'Oméga, rayon violet de Ses Yeux ! - A. Rimbaud "Voyelles" >>#
- Output:
A noir, E blanc, I rouge, U vert, O bleu : voyelles, Je dirai quelque jour vos naissances latentes : A, noir corset velu des mouches éclatantes Qui bombinent autour des puanteurs cruelles, Golfes d'ombre ; E, candeur des vapeurs et des tentes, Lances des glaciers fiers, rois blancs, frissons d'ombelles ; I, pourpres, sang craché, rire des lèvres belles Dans la colère ou les ivresses pénitentes ; U, cycles, vibrements divins des mers virides, Paix des pâtis semés d'animaux, paix des rides Que l'alchimie imprime aux grands fronts studieux ; O, suprême Clairon plein des strideurs étranges, Silences traversés des Mondes et des Anges : - O l'Oméga, rayon violet de Ses Yeux ! - A. Rimbaud "Voyelles"
Elixir
In Elixir, one can use either a pair of triple single-quotation marks or a pair of triple double-quotation marks, but in both cases, string interpolation occurs: <lang elixir>IO.puts """ привет мир """</lang> produces:<lang sh>привет мир</lang>
Here is an illustrative iex transcript: <lang elixir>iex(1)> a=2 2 iex(2)> ...(2)> 1 + 1 = #{a} ...(2)> '1 + 1 = 2\n' iex(3)> iex(3)> 2
- (SyntaxError) iex:3: heredoc start must be followed by a new line after
iex(3)></lang>
Erlang
Multiline strings look like this in the Erlang shell: <lang Erlang> 2> S = " ad 2> 123 2> the end". 3> io:fwrite( S ).
ad
123 the end </lang>
F#
All the usual string variations are no HEREDOCs, because they don't comply to this requirement:
The text block will then start on the next line, and will be followed by the chosen token at the beginning of the following line, which is used to mark the end of the textblock.
That said, as with other languages, F# has two string syntax variations which come close:
- verbatim strings
- begin with
@"and end with the next single double quote". A double quote in the string has to be quoted by doubling it. All other characters can be in such a string as-is, including newlines. - tripple-quoted strings
- are delimited by
"""on both ends and can contain any character other than the delimiter sequence of three double quote characters.
Full information on F# strings can be found in MSDN.
Factor
Factor strings surround by '"' are multiline, but accept escape sequences (like "\n", "\uxxxxxxxx"). Strings surrounded by '"""' don't have to escape '"'. Use HEREDOC: (and other variants) for verbatim text <lang factor>" a multiline string\n(with escape sequences: \u{greek-capital-letter-sigma}) " """this is "easier"..""" HEREDOC: EOF
this is not \n escaped at all
EOF</lang>
Forth
version 1
<lang Forth>\ GForth specific words: \ under+ ( a b c -- a+c b) , latest ( -- nt ) , name>string ( nt -- ca u ) \ Should not be a problem to modify it to work with other Forth implementation:
- $! ( ca u -- a )
dup >R dup , here swap move R> allot ;
- $@ ( a -- ca u )
dup @ 1 cells under+ ;
- c!+ ( c ca - ca+1 )
tuck c! 1+ ;
- $!+ ( a u a' -- a'+u ; string-store-plus )
2dup + >R swap move R> ;
\ --- UNIX end-of-line adapted words 10 constant EOL
- input-fix ( -- ; for interactive use ! )
source-id 0= IF cr THEN ;
- get_line ( -- ca u ) EOL parse input-fix ;
- EOL!+ ( a -- a' ; eol-store-plus ) EOL swap c!+ ;
- EOD ( -- ca u ; end-of-doc )
latest name>string ;
- >> ( "doc-name" "doc-body" -- ) input-fix
CREATE 0 , \ post body length
here dup >R
BEGIN refill >R
get_line 2dup EOD compare
R> AND \ notEOD && input-stream ->
WHILE rot $!+ EOL!+
REPEAT 2drop
R> tuck - dup allot
swap -1 cells + ! \ fixup body length
DOES> ( -- ca u ) $@ ;
\ TEST ; excerpt from Project Gutenberg 'Alice in Wonderland'
>> ALICE CHAPTER I. Down the Rabbit-Hole
Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, 'and what is the use of a book,' thought Alice 'without pictures or conversation?' ALICE >> RABBIT RABBIT ALICE type ." --" cr RABBIT type</lang>
CHAPTER I. Down the Rabbit-Hole Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, 'and what is the use of a book,' thought Alice 'without pictures or conversation?' --
version 2
Here's a slightly different implementation, with less stack juggling. It does not echo linefeeds in interactive mode, but that can easily be added.
It's written to works with Forth's default implementation of counted strings. Those are limited to 255 characters, which is fine in many cases, but on the short side for here documents, so therefore we temporarily redefine them to use a full cell for size (16 bits would probably be ideal) while compiling the here document words. <lang Forth>get-current get-order wordlist swap 1+ set-order definitions
- place over >r rot over cell+ r> move ! ;
- +place 2dup >r >r dup @ cell+ + swap move r> r> dup @ rot + swap ! ;
- count dup cell+ swap @ ;
set-current
CREATE eol 10 C, DOES> 1 ; CREATE eod 128 ALLOT DOES> count ;
- seteod 0 parse ['] eod >body place ;
- start 0 0 here place ;
- read refill 0= IF abort" Unterminated here document" THEN ;
- ~end source eod compare ;
- store source here +place eol here +place ;
- slurp BEGIN read ~end WHILE store REPEAT refill drop ;
- totalsize here count + here - ;
- finish totalsize ALLOT align ;
- << seteod start slurp finish DOES> count ;
previous
( Test )
CREATE Alice << ~~ end ~~ They got a building down New York City, it’s called Whitehall Street, Where you walk in, you get injected, inspected, detected, infected, Neglected and selected. ~~ end ~~
Alice type bye</lang>
- Output:
They got a building down New York City, it’s called Whitehall Street, Where you walk in, you get injected, inspected, detected, infected, Neglected and selected.
Fortran
In Fortran, spaces outside text literals are nowhere significant, not even within words, so that GOTO = G OTO = GO TO and there are no reserved words either so GOTO might be the name of a variable as well and both can be used in the same source. Statements were originally specified with a special format: columns one to five were for statement labels (integers only, not zero), column six specified a continuation line if not blank or zero, and columns 73-80 were for sequence numbers in case you dropped the deck of cards. Thus, source was found in columns 7-72, and layout of the source could be varied without effect on the results. Originally, the only way to produce text in the output (as for annotating the numerical results) was via the "Hollerith" format code, of the form nH where n specified the exact count of characters following the H. Any characters. Miscounts would cause a syntax error - if you were lucky! Happily, a quoted literal syntax was soon introduced, using apostrophes as delimiters with two apostrophes in a row signifying a contained apostrophe. Later, either an apostrophe or a double quote could be used to start a text string (and the same one must be used to end it) so that if one or the other were desired within a text literal, the other could be used as its delimiters. If both were desired, then there would be no escape from doubling for one.
Producing a source file containing a block of text that will be presented as output in the same layout (new lines and all) is only possible if the added layout stuff (generating the required new line starts) and delimiters in the source are disregarded. But if one accepts a few constraints, the following shows a possible approach: <lang Fortran>
INTEGER I !A stepper.
CHARACTER*666 I AM !Sufficient space.
I AM = "<col72
C 111111111122222222223333333333444444444455555555556666666666 C 123456789012345678901234567890123456789012345678901234567890123456789
1 <col72
2 I AM <col72
3 <col72
4 THAT I AM <col72
5"
Chug through the text blob.
DO I = 0,600,66 !Known length.
WRITE (6,1) I AM(I + 1:I + 66) !Reveal one line.
1 FORMAT (A66) !No control characters are expected.
END DO !On to the next line.
END
</lang> With old-style fixed-format source, rather amusingly there is space for sixty-six characters of text per line and so this is the canvas. Any usage of tab characters must be resolved into spaces (and some compilers count up to 72 oddly when tabs are involved) and likewise with new lines. A surprise was provided to an old-time card flapper when it became apparent that trailing spaces were not being incorporated into the text literal unless the "<col72" markers were appended to column seventy-two of the source. An old-time card deck copied to disc and with the sequence numbers in columns 73-80 removed (as no-one is going to drop a disc file so some storage space can be saved) might thereby compile incorrectly! Similarly, the source text highlighter here does not fully recognise the odd tricks available for Fortran syntax, apparently deeming the comments a part of a text literal. The F90 compiler's highlighting does, and shows that text beyond column 72 is not Fortran code.
The text blob could instead be an array, but in that case, each line would have to be delimited by quotes and a comma added, reducing the width of the canvas and adding more stuff to be disregarded. But with a single blob of text, the output statement must step through the parts of the blob to extract the lines. If the statement were WRITE (6,1) I AM then only the first 66 characters of I AM would be rolled forth. If the format code were just A instead of A66, then all the text would be rolled, but the output would not be presented with 66 characters per line. So, some complications lead to :
I AM
THAT I AM
Free Pascal
In Pascal, the only forbidden character in string literals is the newline character. However, as of 2019‑09‑06 in a trunk version of the FPC (Free Pascal compiler) support for string literals spanning multiple lines can be enabled.
Frink
Frink does not have awkward here-docs. Triple-quoted strings serve the same purpose, but more concisely. (The Perl, PHP, etc. syntax for here-documents is a violation of the "define everything at most once" principle of software engineering.) Variable interpolation is allowed within triple-quoted strings. <lang frink> lyrics = """Oh, Danny Boy, The pipes, the pipes are calling From glen to glen and down the mountainside""" </lang>
Genie
Genie includes triple quoted verbatim strings and "at" quoted template strings, which can be used as Heredoc data in source. Given the limitation of terminating quotes not being a user defined sequence, inner quotations will need to be escaped or transcluded.
<lang genie>[indent=4] /*
Here documents, as template and verbatim strings in Genie valac heredoc.gs
- /
init
test:string = "Genie string"
var multilineString = """
this is a $test """
var templateString = @"
this is a $test template with math for six times seven = $(6 * 7) "
stdout.printf("%s", multilineString)
stdout.printf("%s", templateString)</lang>
- Output:
prompt$ valac heredoc.gs prompt$ ./heredoc this is a $test this is a Genie string template with math for six times seven = 42
Go
Go does not have here documents. Multiline string literals serve this purpose.
<lang go>var m = ` leading spaces
and blank lines`</lang>
Groovy
Groovy has two types of multi-line strings, which behave similarly to "here documents"
Multi-line String literal
The literal text, preserving lines and spacing <lang groovy>println Time's a strange fellow;
more he gives than takes
(and he takes all) nor any marvel finds quite disappearance but some keener makes losing, gaining
--love! if a world ends
</lang>
- Output:
Time's a strange fellow;
more he gives than takes
(and he takes all) nor any marvel finds
quite disappearance but some keener makes
losing, gaining
--love! if a world ends
Multi-line GString expression
Like single-line GString expressions, any subexpression delimited with ${ } is substituted with its "toString()" value. Preserves lines and spacing outside of the subexpressions. <lang groovy>def expired='defunct' def horse='stallion' def christ='Jesus'
println """ Buffalo Bill's
${expired}
who used to
ride a watersmooth-silver
${horse}
and break onetwothreefourfive pigeonsjustlikethat
${christ}
he was a handsome man
and what i want to know is
how do you like your blueeyed boy
Mister Death
"""</lang>
- Output:
Buffalo Bill's
defunct
who used to
ride a watersmooth-silver
stallion
and break onetwothreefourfive pigeonsjustlikethat
Jesus
he was a handsome man
and what i want to know is
how do you like your blueeyed boy
Mister Death
Haskell
You could use raw-strings-qq, or alternatively:
<lang Haskell>
main :: IO () main = do
-- multiline String
putStrLn "Hello\
\ World!\n"
-- more haskell-ish way
putStrLn $ unwords ["This", "is", "an", "example", "text!\n"]
-- now with multiple lines
putStrLn $ unlines [
unwords ["This", "is", "the", "first" , "line."]
, unwords ["This", "is", "the", "second", "line."]
, unwords ["This", "is", "the", "third" , "line."]
]
</lang>
Output:
Hello World! This is an example text! This is the first line. This is the second line. This is the third line.
J
<lang j>here=:0 :0
0 :0 will be replaced by the text on the following lines. This is three tokens: two instances of the number 0 and one instance of the explicit definition token ':'. Any indentation in the here document will be retained in the result. There must be a space to the left of : or it will combine with the 0 on its left to form the token 0: which is something completely different.
The here document is terminated by a line which contains only a single right parenthesis ')' and optional white space. In J's documentation the family of entities which include here documents (and verb definitions and so on) are called 'scripts'.
When several scripts are referenced on the same line, they are used sequentially in an order determined by their appearance on the line. The leftmost 'script' reference gets the last script and the rightmost reference gets the first script. But this is a rare usage.
Typically, such values are assigned a name so that they can be used later. However, they may also be discarded and/or ignored, in which case they are logically equivalent to multi-line comments.
)
and_here=:noun define
'noun define' is an alternative and perhaps more "user friendly" way of declaring a here document. It achieves the same thing as 0 :0 and in fact 'noun' has the value 0 and 'define' has the value :0 And, of course, there must be a space between the word 'noun' and the word 'define'.
Other useful alternatives include verb (which has the value 3) and dyad (which has the value 4), and adverb (which has the value 1). In other words 'verb define' (if unquoted) would be replaced by a verb whose definition is provided in the following 'script'. However, all of these names are normal variables which can be declared to have different values by the developer. And, of course, note that this mechanism is significantly more verbose than using the underlying 0 :0 mechanism directly.
)</lang>
JavaScript
ES6
ES6 introduced template literals. These are string literals that suport multi-line text and can include interpolated expressions using ${···} syntax. It is indicated with the backtich character [`] <lang JavaScript>const myVar = 123; const tempLit = `Here is some multi-line string. And here is the value of "myVar": ${myVar} That's all.`; console.log(tempLit) </lang>
Here is some multi-line string. And here is the value of "myVar": 123 That's all.
jq
No special syntax is required to support "here documents" in jq in that any JSON string, and indeed any string specifier (as explained below), can be presented using a multiline format.
For example, consider:<lang jq> def s: "x y z";
s</lang>
- Output:
<lang sh>$ jq -n s.jq "x\ny\nz"</lang>
String specifiers, that is possibly non-JSON strings which incorporate references to jq expressions, are handled in the same way. For example, the following program produces the same result: <lang jq>def specifier(a): "x \(a) z";
specifier("y")</lang>
Most control characters, such as Control-A and Control-Z, can also be presented literally, but the RosettaCode.org editor disallows them in general, so the next example only shows an embedded literal tab: <lang jq>"a tab: end parens:() single quotation mark:' double quotation mark must be escaped:\" b d"</lang>
- Output:
<lang sh>"a\ntab:\tend\nparens:()\nsingle quotation mark:'\ndouble quotation mark must be escaped:\"\nb\nd"</lang>
Julia
Like Python, Julia has triple-quoted string literals, which are similar to here-docs:
<lang julia>print("""\ Usage: thingy [OPTIONS]
-h Display this usage message
-H hostname Hostname to connect to
""")</lang>
Kotlin
Kotlin's 'raw string literals' behave in a similar way to 'here' documents in that line breaks, indentation and other whitespace is preserved within the string. They are distingished from normal strings by being surrounded by triple quote characters rather than by single quotes.
Escaped characters (such as \n, \t etc.) do not have a special meaning and so are treated literally.
It's also possible to embed variables and other expressions in a raw string literal using Kotlin's string interpolation facilities.
Here's an example of all this: <lang scala>// version 1.1.0
fun main(args: Array<String>) {
val ev = "embed variables"
val here = """
This is a raw string literal
which does not treat escaped characters
(\t, \b, \n, \r, \', \", \\, \$ and \u)
specially and can contain new lines,
indentation and other whitespace
within the string.
"Quotes" or doubled ""quotes"" can be included without problem but not tripled quotes.
It's also possible to $ev
in a raw string literal using string
interpolation.
If you need to include a
literal ${'$'} sign in a raw string literal then
don't worry you've just done it!
"""
println(here)
}</lang>
- Output:
This is a raw string literal
which does not treat escaped characters
(\t, \b, \n, \r, \', \", \\, \$ and \u)
specially and can contain new lines,
indentation and other whitespace
within the string.
"Quotes" or doubled ""quotes"" can
be included without problem but not
tripled quotes.
It's also possible to embed variables
in a raw string literal using string
interpolation.
If you need to include a
literal $ sign in a raw string literal then
don't worry you've just done it!
Lambdatalk
Lambdatalk inverts the standard evaluation process, nothing is evaluated out of S-expressions {first rest}.
<lang scheme> 1) defining a variable: {def myVar 123}
2) defining some text: Here is some multi-line string. And here is the value of "myVar": '{myVar} That's all.
3) displays :
Here is some multi-line string. And here is the value of "myVar": 123 That's all. </lang>
langur
Use a block modifier on a string literal using the q or Q form to generate a blockquote. The block modifier must be the last modifier.
<lang langur>val .s = q:block END
We put our text here. Here we are, Doc.
END</lang>
We can also use this with a regex literal. Note that this does not make the regex pattern "free-spacing." Use the x modifier for that.
<lang langur>val .re = re:block END a regex pattern here Still here, Doc. END</lang>
<lang langur>val .re = re:x:block END
a free-spacing regex pattern here Somewhere, Doc.
END</lang>
Lingo
Lingo has no heredoc syntax. Quotes inside string literals have to be escaped with ""E&".
But you can define multi-line strings using the line continuation character "\":
<lang lingo>str = "This is the first line.\ This is the second line.\ This ""E&"line""E&" contains quotes."
put str</lang>
- Output:
This is the first line. This is the second line. This "line" contains quotes.
For longer text it's more comfortable to put it into a named "field member" (=asset container) and load its text into a variable when needed:<lang lingo>str = member("my long text").text put str</lang>
Lua
Lua uses the [ [ to mark the start of a dochere block and ] ] to mark the end. It can be used directly or while assigning strings to a variable. An arbitrary but matching number of = may be placed between the brackets in both delimiters to allow ] ] to appear in the string. <lang lua> print([[ This is a long paragraph of text it is the simplest while using it with lua, however it will have the same line breaks and spacing as
you set in this block.
]])
print([=[by using equals signs, ]] may be embedded.]=])
local msg = [[this is a message that spans multiple lines and will have the next lines preserved as they were entered, so be careful when using this]]
print(msg)
</lang>
M2000 Interpreter
A block of { } can be used for code and for text. Editor in M2000 environment can color code/string on the fly, analyzing the first line, where the block start. <lang M2000 Interpreter> Module Checkit {
a$={This is the first line
This is the second line
End bracket position declare indentation fortext (except for first line)
}
Report a$ ' print all lines, without space at the left
} CheckIt </lang>
Mathematica / Wolfram Language
<lang Mathematica>Print["Mathematica
is an
interesing
language, with its strings being multiline by\ default when not
back\ s\\ashed!"];</lang>
- Output:
Mathematica is an interesing language, with its strings being multiline by default when not backs\ashed!
NewLISP
<lang NewLISP>; here-document.lsp
- oofoe 2012-01-19
- http://rosettacode.org/wiki/Here_document
(print (format [text]
Blast it %s! I'm a %s,
not a %s!
--- %s
[/text] "James" "magician" "doctor" "L. McCoy"))
(exit)</lang>
- Output:
Blast it James! I'm a magician,
not a doctor!
--- L. McCoy
Nim
There are no heredocs, but triple-quoted-strings can be used: <lang nim>echo """Usage: thingy [OPTIONS]
-h Display this usage message
-H hostname Hostname to connect to
"""</lang>
NMAKE.EXE
<lang nmake.exe>target0: dependent0
command0 <<
temporary, discarded inline file ... <<
target1: dependent1
command1 <<
temporary, but preserved inline file ... <<KEEP
target2: dependent2
command2 <<filename2
named, but discarded inline file ... <<NOKEEP
target3: dependent3
command3 <<filename3
named and preserved inline file ... <<KEEP</lang>
OCaml
<lang ocaml> print_string {whatever|
'hahah', `this`
<is>
\a\
"Heredoc" ${example}
in OCaml
|whatever}
</lang>
- Output:
'hahah', `this`
<is>
\a\
"Heredoc" ${example}
in OCaml
OxygenBasic
Use the keyword quote followed by a keyword or group of symbols to mark the beginning and end of text
s=quote
""""
She said "He said 'I said `There is a rumour
going around.` ' "
""""
print s
Perl
In Perl, there must not be a space between the "<<" and the token string. By default, the ending token must the entire end line (i.e. no surrounding spaces) for it to be recognized (but see exception below). Interpolation is allowed, like a double-quoted string:
<lang perl>$address = <<END; 1, High Street, $town_name, West Midlands. WM4 5HD. END</lang>
If the token string contains spaces, the token after the "<<" must be quoted; otherwise the double-quotes is implicit: <lang perl>$pancake = <<"NO MORE INGREDIENTS"; egg milk flour NO MORE INGREDIENTS</lang>
It is possible to make a here-document that behaves differently than a double-quoted string, by applying a different kind of quoting to the token. For example, if you use single quotes, then the here document will not support interpolation, like a normal single-quoted string:
<lang perl>$x = <<'FOO'; No $interpolation here FOO</lang>
Alternately, you can use backticks to cause the here document to be executed and the result returned, just like a normal backtick operator:
<lang perl>$output = <<`BAR`; ls /home BAR</lang>
Note that in the above examples, that a semicolon was left after the here document's token string. This is because (unlike PHP) the here document does not start immediately at the "<<END" token -- it starts on the next line. The "<<END" is actually an expression, whose value will be substituted by the contents of the here document. The "<<END" must still live inside a valid statement on the line that it's used. To further illustrate this fact, we can use the "<<END" inside a complex, nested expression:
<lang perl>print(<<EOF . "lamb\n"); Mary had
a little
EOF</lang>
Since Perl 5.26, the here document can be indented by putting a '~' before the token. All spaces to the left of the ending token then become insignificant. This avoids having a disconcerting exdent in the middle of your code.
<lang perl>sub flibbertigibbet {
print <<~END;
Mary had
a little
lamb
END
}</lang>
Phix
Phix does not have here-docs. In Phix normal double quoted strings are single line and require escaping. Strings can also be entered by using triple doublequotes or single backticks to include linebreaks and avoid any backslash interpretation. If the literal begins with a newline, it is discarded and any immediately following leading underscores specify a (maximum) trimming that should be applied to all subsequent lines. Interpolation is left to printf and friends. Both """`""" and `"""` are valid. Examples: <lang Phix>string ts1 = """ this "string"\thing"""
string ts2 = """this "string"\thing"""
string ts3 = """ _____________this
"string"\thing"""
string ts4 = ` this "string"\thing`
string ts5 = `this "string"\thing`
string ts6 = ` _____________this
"string"\thing`
string ts7 = "this\n\"string\"\\thing"
constant tests={ts1,ts2,ts3,ts4,ts5,ts6,ts7} for i=1 to length(tests) do
for j=1 to length(tests) do
if tests[i]!=tests[j] then crash("error") end if
end for
end for printf(1,""" ____________Everything
(all %d tests)
works
just
file.""",length(tests))
printf(1,"""`""") printf(1,`"""`)</lang>
- Output:
Everything (all 7 tests) works just file.`"""
PHP
In PHP, the here document symbol is 3 less-than signs, not two: <<<
There must not be a space between the "<<<" and the token string. The ending token must always be the entire end line (i.e. no surrounding spaces) for it to be recognised, except for a possible semicolon. Interpolation is allowed, like a double-quoted string:
<lang php>$address = <<<END 1, High Street, $town_name, West Midlands. WM4 5HD. END;</lang>
In PHP 5.3+, it is possible to make a here-document that does not interpolate (PHP calls this a "nowdoc"), by surrounding the token with single-quotes (like in Perl):
<lang php>$x = <<<'FOO' No $interpolation here FOO;</lang>
PicoLisp
We can use the 'here' function:
<lang PicoLisp>(out "file.txt" # Write to "file.txt"
(prinl "### This is before the text ###") (here "TEXT-END") (prinl "### This is after the text ###") )
"There must be some way out of here", said the joker to the thief "There's too much confusion, I can't get no relief" TEXT-END
(in "file.txt" (echo)) # Show "file.txt"</lang>
- Output:
### This is before the text ### "There must be some way out of here", said the joker to the thief "There's too much confusion, I can't get no relief" ### This is after the text ###
PowerShell
In PowerShell, here-docs are known as "Here-Strings". The Key is the At symbol @.
<lang PowerShell> $XMLdata=@" <?xml version="1.0" encoding="utf-8"?> <unattend xmlns="urn:schemas-microsoft-com:unattend">
<servicing>
<package action="configure">
<assemblyIdentity name="Microsoft-Windows-Foundation-Package" version="${strFullVersion}" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="" />
<selection name="RemoteServerAdministrationTools" state="true" />
<selection name="RemoteServerAdministrationTools-Roles-AD" state="true" />
<selection name="RemoteServerAdministrationTools-Roles-AD-DS" state="true" />
<selection name="RemoteServerAdministrationTools-Roles-AD-DS-SnapIns" state="true" />
<selection name="RemoteServerAdministrationTools-Features-StorageManager" state="true" />
<selection name="RemoteServerAdministrationTools-Features-Wsrm" state="true" />
</package>
</servicing>
<cpi:offlineImage cpi:source="wim:d:/2008r2wim/install.wim#Windows Server 2008 R2 SERVERSTANDARD" xmlns:cpi="urn:schemas-microsoft-com:cpi" />
</unattend> "@ </lang>
Python
Python does not have here-docs. It does however have triple-quoted strings which can be used similarly.
<lang python>print("""\ Usage: thingy [OPTIONS]
-h Display this usage message
-H hostname Hostname to connect to
""")</lang>
Racket
Racket has a raw built-in here-document syntax, with the usual problems that this implies (breaks code indentation, no "interpolation"):
<lang Racket>
- lang racket/base
(displayln #<<EOF
Blah blah blah with indentation intact and "free" \punctuations\
EOF ) </lang>
- Output:
Blah blah blah
with indentation intact
and "free" \punctuations\
In addition, Racket has "@-forms", which are a syntax for free text (described here) that works well with code:
<lang Racket>
- lang at-exp racket/base
(require scribble/text)
(define excited "!!!") (define (shout . text) @list{>>> @text <<<})
(output
@list{Blah blah blah
with indentation intact
but respecting the indentation of
the whole code
and "free" \punctuations\
and even string interpolation-like @excited
but really @shout{any code}
})
(output @list|<<{And customizable delimiters
so @foo{} is just plain text}>>|)
</lang>
- Output:
Blah blah blah
with indentation intact
but respecting the indentation of
the whole code
and "free" \punctuations\
and even string interpolation-like !!!
but really >>> any code <<<
And customizable delimiters
so @foo{} is just plain text
Raku
(formerly Perl 6)
Heredocs in Raku use the :to modifier to a quoting operator,
such as q or qq.
The indentation of the end marker is removed from every line.
<lang perl6>my $color = 'green'; say qq :to 'END';
some line color: $color another line END</lang>
- Output:
some line color: green another line
Note that the quotes around the "END" are not magic --- the marker is just a regular string; it's the `q` or `qq` that decides whether or not the heredoc interpolates.
Multiple here docs may be stacked on top of each other.
<lang perl6>my $contrived_example = 'Dylan'; sub freewheelin() {
print q :to 'QUOTE', '-- ', qq :to 'AUTHOR';
I'll let you be in my dream,
if I can be in yours.
QUOTE
Bob $contrived_example
AUTHOR
}
freewheelin;</lang>
- Output:
I'll let you be in my dream,
if I can be in yours.
-- Bob Dylan
Both q and qq are specialised forms of Q which comes with many adverbs. Here a heredoc that only interpolates @-sigils.
<lang perl6>my @a = <1 2 3 4>; say Q :array :to 'EOH';
123 \n '"`
@a$bc
@a[]
EOH</lang>
- Output:
123 \n '"`
@a$bc
1 2 3 4
Raven
As a list: <lang Raven>'Buffy the Vampire Slayer' as sender 'Spike' as recipient
[ "Dear %(recipient)s, " "I wish you to leave Sunnydale and never return. " "Not Quite Love, "%(sender)s ] "\n" join print </lang> Using group to place the data on the stack: <lang Raven>'Buffy the Vampire Slayer' as sender 'Spike' as recipient
group
"Dear %(recipient)s,
"
"I wish you to leave Sunnydale and never return.
"
"Not Quite Love,
%(sender)s\n"
list "\n" join print </lang>
- Output:
Dear Spike, I wish you to leave Sunnydale and never return. Not Quite Love, Buffy the Vampire Slayer
REXX
<lang rexx>/*REXX program demonstrates a method to use "here" documents in REXX. */ parse arg doc . /*"here" name is case sensitive. */
do j=1 for sourceline()
if sourceline(j)\=='◄◄'doc then iterate
do !=j+1 to sourceline() while sourceline(!)\=='◄◄.'
say sourceline(!)
end /*!*/
exit /*stick a fork in it, we're done.*/
end /*j*/
say doc '"here" document not found.' exit /*stick a fork in it, we're done.*/ /*──────────────────────────────────start of "here" docs────────────────── ◄◄rs-232 RS─232 Signals and Pinouts ┌─────────────────────────────────────────────────┐
│13 12 11 10 9 8 7 6 5 4 3 2 1│
──► Interface between data └┐ 25 24 23 22 21 20 19 18 17 16 15 14┌┘ terminal equipment (DTE/male)└───────────────────────────────────────────────┘ and data communication equipment [DCE/female] employing serial ┌───────────────────────────────────────────┐ binary data interchange. │ 12◄─secondary carrier detect [SCD] DCE │ ┌─────────────────────────────────┤ 13◄─secondary clear to send [SCS] DCE │ │ 1◄─protective ground [PG, GND] │ 14◄─secondary transmitted data [STD] DTE │ │ 2◄─transmitted data [TD] DTE │ 15◄─transmit clock [TC] DCE │ │ 3◄─received data [RD] DCE │ 16◄─secondary received data [SRD] DCE │ │ 4◄─request to send [RTS] DTE │ 17◄─receiver clock [RC] DCE │ │ 5◄─clear to send [CTS] DCE │ 18◄─unassigned │ │ 6◄─data set ready [DSR] DCE │ 19◄─secondary request to send [SRS] DTE │ │ 7◄─signal ground [SG] │ 20◄─data terminal ready [DTR] DTE │ │ (common return) │ 21◄─signal quality detector [SQD] DCE │ │ 8◄─carrier detect [CD] DCE │ 22◄─ring indicator [RI] DCE │ │ 9◄─positive voltage [-] │ 23◄─data rate select [DRS] DCE/DTE │ │10◄─negative voltage [-] │ 24◄─external clock [XTC] DTE │ │11◄─unassigned │ 25◄─unassigned │ └─────────────────────────────────┴───────────────────────────────────────────┘ ◄◄. ◄◄can
┌──────┐
│ │
│ ├┐
│ ├┘
│ │
│ │
│ │
│ │
│ │ ┌─────┐
└──┬┬──┘ │┌───┐│
││ ├┤ ├┤
││ ┌───────────────┐ ││ ││
││ ┌┴──────────────┬┘ └┤ ├┘
│└───┤ │ └───┘
└────┤ ┌──┘
│ │
└──┐ │
│ │
│ │
│ │
└─────────┘
◄◄. ────────────────────────────────────end of "here" docs──────────────────*/</lang>
- Output:
when using the input of
RS─232 Signals and Pinouts ┌─────────────────────────────────────────────────┐
│13 12 11 10 9 8 7 6 5 4 3 2 1│
──► Interface between data └┐ 25 24 23 22 21 20 19 18 17 16 15 14┌┘
terminal equipment (DTE/male)└───────────────────────────────────────────────┘
and data communication equipment
[DCE/female] employing serial ┌───────────────────────────────────────────┐
binary data interchange. │ 12◄─secondary carrier detect [SCD] DCE │
┌─────────────────────────────────┤ 13◄─secondary clear to send [SCS] DCE │
│ 1◄─protective ground [PG, GND] │ 14◄─secondary transmitted data [STD] DTE │
│ 2◄─transmitted data [TD] DTE │ 15◄─transmit clock [TC] DCE │
│ 3◄─received data [RD] DCE │ 16◄─secondary received data [SRD] DCE │
│ 4◄─request to send [RTS] DTE │ 17◄─receiver clock [RC] DCE │
│ 5◄─clear to send [CTS] DCE │ 18◄─unassigned │
│ 6◄─data set ready [DSR] DCE │ 19◄─secondary request to send [SRS] DTE │
│ 7◄─signal ground [SG] │ 20◄─data terminal ready [DTR] DTE │
│ (common return) │ 21◄─signal quality detector [SQD] DCE │
│ 8◄─carrier detect [CD] DCE │ 22◄─ring indicator [RI] DCE │
│ 9◄─positive voltage [-] │ 23◄─data rate select [DRS] DCE/DTE │
│10◄─negative voltage [-] │ 24◄─external clock [XTC] DTE │
│11◄─unassigned │ 25◄─unassigned │
└─────────────────────────────────┴───────────────────────────────────────────┘
- Output:
when using the input of
┌──────┐
│ │
│ ├┐
│ ├┘
│ │
│ │
│ │
│ │
│ │ ┌─────┐
└──┬┬──┘ │┌───┐│
││ ├┤ ├┤
││ ┌───────────────┐ ││ ││
││ ┌┴──────────────┬┘ └┤ ├┘
│└───┤ │ └───┘
└────┤ ┌──┘
│ │
└──┐ │
│ │
│ │
│ │
└─────────┘
Ring
<lang ring> text =" <<'FOO' Now
is
the
time
for
all
good mem
to come to the aid of their country." see text + nl </lang> Output:
<<'FOO'
Now
is
the
time
for
all
good mem
to come to the aid of their country.
Ruby
In Ruby, there must not be a space between the "<<" and the token string. The ending token must always be the entire end line (i.e. no surrounding spaces) for it to be recognised, unless you use "<<-" instead of "<<", in which case indentation before the ending token is allowed. Interpolation is allowed, like a double-quoted string:
<lang ruby>address = <<END 1, High Street,
- {town_name},
West Midlands. WM4 5HD. END</lang>
If the token string contains spaces, the token after the "<<" must be quoted; otherwise the double-quotes is implicit:
<lang ruby>pancake = <<"NO MORE INGREDIENTS" egg milk flour NO MORE INGREDIENTS</lang>
It is possible to make a here-document that behaves differently than a double-quoted string, by applying a different kind of quoting to the token. For example, if you use single quotes, then the here document will not support interpolation, like a normal single-quoted string:
<lang ruby>x = <<'FOO' No
- {interpolation}
here FOO</lang>
Alternately, you can use backticks to cause the here document to be executed and the result returned, just like a normal backtick operator:
<lang ruby>output = <<`BAR` ls /home BAR</lang>
The here document does not start immediately at the "<<END" token -- it starts on the next line. The "<<END" is actually an expression, whose value will be substituted by the contents of the here document. The "<<END" must still live inside a valid statement on the line that it's used. To further illustrate this fact, we can use the "<<END" inside a complex, nested expression:
<lang ruby>puts <<EOF + "lamb" Mary had
a little
EOF</lang>
Run BASIC
<lang runbasic>text$ =" <<'FOO' Now
is
the
time
for
all
good mem
to come to the aid of their country." print text$</lang>
- Output:
<<'FOO'
Now
is
the
time
for
all
good mem
to come to the aid of their country.
Rust
Similar to C++, Rust offers raw strings. In a manner resembling Lua's delimiters, an arbitrary but matching number of # on both ends may be used to allow inclusion of # into the string:
<lang rust>let x = r#"
This is a "raw string literal," roughly equivalent to a heredoc.
"#;
let y = r##"
This string contains a #.
"##; </lang>
Scala
All versions
Scala multiline literal are called raw strings. Triple quotes (""") marks the beginning and end. Specially handy when using escape sequences in e.g. regular expressions.
<lang Scala>object temp {
val MemoriesOfHolland=
"""Thinking of Holland |I see broad rivers |slowly chuntering |through endless lowlands, |rows of implausibly |airy poplars |standing like tall plumes |against the horizon; |and sunk in the unbounded |vastness of space |homesteads and boweries |dotted across the land, |copses, villages, |couchant towers, |churches and elm-trees, |bound in one great unity. |There the sky hangs low, |and steadily the sun |is smothered in a greyly |iridescent smirr, |and in every province |the voice of water |with its lapping disasters |is feared and hearkened.""".stripMargin
}</lang> All control codes are transparent e.g. new lines. In order for a neat code each lines has as prefix spaces and a | symbol which will be removed by the stripMargin function.
SenseTalk
SenseTalk has "block quotes" for large blocks of text, enclosed between "{{" (at the end of a line) and "}}" (at the beginning of a line). A tag can also be used after the "{{" and before the "}}" which allows for nesting of blocks, such as for a block of code containing other block quotes.
<lang sensetalk> set script to {{SCRIPT put "Script demonstrating block quotes"
set text to {{ "I wish it need not have happened in my time," said Frodo. "So do I," said Gandalf, "and so do all who live to see such times. But that is not for them to decide. All we have to decide is what to do with the time that is given us." }}
put the number of occurrences of "time" in text --> 3
SCRIPT}}
do script
</lang>
SequenceL
<lang sequencel>main := "In SequenceL strings are multiline by default. 'All' non-\" characters are valid for inclusion in a string.";</lang>
- Output:
"In SequenceL strings are multiline by default. 'All' non-" characters are valid for inclusion in a string."
Sidef
There must not be a space between the "<<" and the token string. When the token string is double-quoted ("") or not quoted, the content will be interpolated like a double-quoted string: <lang ruby>var text = <<"EOF"; a = #{1+2} b = #{3+4} EOF</lang>
If single quotes are used, then the here document will not support interpolation, like a normal single-quoted string: <lang ruby>var x = <<'FOO'; No
- {interpolation}
here FOO</lang> The here document does not start immediately at the "<<END" token -- it starts on the next line. The "<<END" is actually an expression, whose value will be substituted by the contents of the here document. To further illustrate this fact, we can use the "<<END" inside a complex, nested expression: <lang ruby>say (<<EOF + "lamb"); Mary had
a little
EOF</lang> which is equivalent with: <lang ruby>say (<<EOF Mary had
a little
EOF + "lamb");</lang>
SQL PL
With SQL only from command line. The single quote string is opened along the three lines: <lang bash> db2 "select 'This is the first line. This is the second line. This is the third line.' from sysibm.sysdummy1" </lang> Output:
1 ------------------------------------------------------------------------ This is the first line. This is the second line. This is the third line. 1 record(s) selected.
With SQL only from script with concat function (one row): <lang sql pl> select 'This is the first line.' || chr(10) || 'This is the second line.' || chr(10) || 'This is the third line.' from sysibm.sysdummy1; </lang> Output:
1 ------------------------------------------------------------------------ This is the first line. This is the second line. This is the third line. 1 record(s) selected.
With SQL only from script with union operator (three rows): <lang sql pl> select 'This is the first line.' from sysibm.sysdummy1 union select 'This is the second line.' from sysibm.sysdummy1 union select 'This is the third line.' from sysibm.sysdummy1; </lang> Output:
1 ------------------------ This is the first line. This is the second line. This is the third line. 3 record(s) selected.
version 9.7 or higher.
With SQL PL: <lang sql pl> SET serveroutput ON CALL DBMS_OUTPUT.PUT_LINE('This is the first line.' || chr(10) || 'This is the second line.' || chr(10) || 'This is the third line.'); </lang> Output:
Return Status = 0 This is the first line. This is the second line. This is the third line.
Tcl
<lang tcl>set hereDocExample { In Tcl, the {curly brace} notation is strictly a here-document style notation as it permits arbitrary content inside it *except* for an unbalanced brace. That is typically not a problem as seen in reality, as almost all content that might be placed in a here-doc is either brace-free or balanced. The content of the braces is not interpreted at all; no substitutions are performed on it.
The sole exception is that there is limited processing of backslashes; a single backslash at the end of a line causes the end-of-line plus all whitespace at the start of the next line to be compressed to a single space. }</lang>
If substitution is desired within the document, it should either be written
inside "double quotes" (instead of {braces}) or it should be passed through the subst command,
which performs another round of substitutions.
TXR
TXR was originally conceived out of the need to have "there documents": parse a document and extract variables, but in a style similar to generation of here documents. Here doc output was added later.
We use @(maybe)/@(or)/@(end) to set up some default values for variables which are overridden from the command line. Unification fails for an overridden variable, which is why we have to separate out the bind directives into the branches of a maybe.
By passing the script to txr using -f we can pass additional command arguments to the resulting script which are interpreted by txr.
<lang txr>#!/usr/bin/txr -f @(maybe) @(bind USER "Unknown User") @(or) @(bind MB "???") @(end) @(output) Dear @USER
Your are over your disk quota by @MB megabytes.
The Computer @(end)</lang>
Test runs
$ ./quota.txr -DMB=20 Dear Unknown User Your are over your disk quota by 20 megabytes. The Computer $ ./quota.txr -DUSER=Bob Dear Bob Your are over your disk quota by ??? megabytes. The Computer $ ./quota.txr -DUSER=Bob -DMB=15 Dear Bob Your are over your disk quota by 15 megabytes. The Computer
Unbound variables throw exceptions:
$ txr -c '@(output) @FOO @(end)' txr: unhandled exception of type query_error: txr: (cmdline:2) bad substitution: FOO
UNIX Shell
In the shell, here document act as input to the command, rather than providing a string definition.
<lang bash>#!/bin/sh cat << ANARBITRARYTOKEN The river was deep but I swam it, Janet. The future is ours so let's plan it, Janet. So please don't tell me to can it, Janet. I've one thing to say and that's ... Dammit. Janet, I love you. ANARBITRARYTOKEN</lang>
<lang bash>cat << EOF Here documents do parameter and command substitution:
* Your HOME is $HOME * 2 + 2 is `expr 2 + 2` * Backslash quotes a literal \$, \` or \\
EOF</lang>
<lang bash>if true; then
cat <<- EOF The <<- variant deletes any tabs from start of each line. EOF
fi</lang>
<lang bash>cat << 'TOKEN' If TOKEN has any quoted characters (like 'TOKEN', "TOKEN" or \TOKEN), then all $ ` \ in the here document are literal characters.
$PATH \$PATH `shutdown now` TOKEN</lang> <lang bash>echo ' In any unix shell, you specify a text block and can use all whitespace like
(spaces) & (tab) in it, by using single quotes.
As mentioned above, a Unix "here document" is a type of redirection. In a literal Bash here document, the starting token must be quoted, but the end token must not, so they are not the same, which does not conform to the task definition. ' </lang>
C Shell
<lang csh>#!/bin/csh -f cat << ANARBITRARYTOKEN
* Your HOME is $HOME * 2 + 2 is `@ n = 2 + 2; echo \$n`
ANARBITRARYTOKEN
cat << 'ANARBITRARYTOKEN' $PATH \$PATH `shutdown now` 'ANARBITRARYTOKEN'</lang>
Ursala
<lang Ursala>hd =
-[ The text enclosed within the so called dash-brackets shown above and below will be interpreted as a list of character strings. It can contain anything except uninterpreted dash-brackets, and can be used in any declaration or expression. The dash-brackets don't have to be on a line by themselves. ]-
example =
-[Some additional facilities allow here-documents to be nested and combined. Writing something like -[ hd ]- within a nested pair of dash-brackets will cause the text declared above (having the identifer hd) to be inserted at that point. The enclosed item can be any expression that evaluates to a list of character strings. We could therefore "escape" a literal dash-bracket within a here-document by writing -[ <'-['> ]-. Dash-brackets can be nested to any depth, alternating between literal text and compiled code on each level.]-
template "x" =
-[A further use of this notation involves defining a text-valued function. The output of this function will be this text, with the argument inserted here -["x"]- and again here -["x"]-. The argument type should be a list of character strings.]-
formletter ("x","y") =
-[Other calling conventions are possible. The left argument comes out here -["x"]- and the right one here -["y"]-.]-
designpattern =
-[A point-free style of function declaration is also supported. The argument comes out here -[. ~& ]-, after being fed through the function appearing within the nested dash-brackets (in this case the identity function). This usage is indicated by a period after the left inner dash-bracket. Nesting is also allowed in point free dash-bracket function specifications.]-
abstractionastronaut =
-[Higher order functions to any level are specified by piling on the periods like this -[.. ~&]-. This one is a second order function that needs to be applied to another function in order to get a first order function such as the previous three examples.]-</lang>
VBScript
There is no such thing in VBScript but we need it, too. The following is a workaround tool.
It will prompt you to select a Txt-based file and do its best to create VBScript code that will recreate that Txt-based file! <lang VBScript> 'Purpose: Converts TXT files into VBS code with a function that returns a text string with the contents of the TXT file ' The TXT file can even be another VBS file.
'History: ' 1.0 8may2009 Initial release ' ' Const ForReading = 1 Const ForWriting = 2 Const ForAppending = 8 Const TristateUseDefault = -2
set WshShell = CreateObject("WSCript.shell")
'File browse dialog box Set objDialog = CreateObject("UserAccounts.CommonDialog") objDialog.Filter = "All Files|*.*" objDialog.InitialDir = WshShell.CurrentDirectory intResult = objDialog.ShowOpen
If intResult = 0 Then
WshShell.Popup "No file selected.", 2, " ", 64 Wscript.Quit
Else
strFileNameIN = objDialog.FileName
End If
strFileNameOUT= strFileNameIN & "_CONVERTED.Vbs"
'Check if strFileNameOUT exists already Set objFSO = CreateObject("Scripting.FileSystemObject") If objFSO.FileExists(strFileNameOUT) then 'does the file EXIST? ' WScript.Echo "found"
OVRWT=MSGBOX(strFileNameOUT & " exists already"&vbCRLF&"Overwrite?",vbYesNoCancel,"Overwrite?")
if OVRWT = 6 then
'proceed
objFSO.DeleteFile(strFileNameOUT)
else
WshShell.Popup "Exiting as requested.", 1, " ", 64
Wscript.Quit
End If
Else ' WScript.Echo "not found" 'strFileNameOUT does NOT exists already
END if
strBaseName=objFSO.GetBaseName(strFileNameIN)
'open strFileNameANSI file, and put entire file into a variable ****SIZE LIMIT ??*****
Set objFile = objFSO.OpenTextFile(strFileNameIN, ForReading)
strText = objFile.ReadAll
objFile.Close
'Start converting
'Convert " to "" strOldText = Chr(34) strNewText = Chr(34)&Chr(34) strText = Replace(strText, strOldText, strNewText)
'Add objTXTFile.writeline (" strOldText = VBCRLF strNewText = """) &vbCrLf"&VBCRLF&" strText=strText& (""" strText = Replace(strText, strOldText, strNewText) 'Converting done
strFileName=objFSO.GetFileName(strFileNameIN)
'Write to file Set objFile = objFSO.OpenTextFile(strFileNameOUT, ForAppending, True) objFile.WriteLine "'this Function will return a string containing the contents of the file called "&strFileName objFile.WriteLine "msgbox "&strBaseName &"()" objFile.WriteLine vbCrLf objFile.WriteLine "Function "&strBaseName&"()" objFile.WriteLine " 'returns a string containing the contents of the file called "&strFileName objFile.WriteLine " Dim strText" objFile.WriteLine " strText= ("""&strText&""") &vbCrLf" objFile.WriteLine " "&strBaseName&"=strText" objFile.WriteLine "End Function" objFile.Close
WshShell.Popup "created " & strFileNameOUT, 3, "Completed", 64 </lang>
XPL0
<lang XPL0>code Text=12; Text(0, " ^"Heredocs^" are pretty much automatic. Multiple lines and whitespace, such as indentations, are output exactly as written. Quote marks (^") and any carets (^^) within the string must be escaped.")</lang>
XSLT
Being a dialect of XML, XSLT inherits CDATA sections. Not quite heredocs, these are more like raw triple quotes in Python (r"""…""") or Scala ("""…""") in that anything except the end delimiter is treated literally.
<lang xml><?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:output method="text"/>
<xsl:template match="/"> <![CDATA[
This text is in a CDATA section. In here, it's okay to include <, >, &, ", and ' without any special treatment.
The section is terminated by a three-character sequence consisting of two right brackets ("]]") followed by a greater-than (">"). If this sequence appears in your text, a workaround is to drop out of the CDATA section, output part of the terminator, then start a new CDATA section and output the rest. Let's do this now:
]]>]]<![CDATA[>
Newlines and spacing are retained as well, as long as they're evaluated in a context that bothers preserving them. Whether or not the spaces before and after the CDATA section are also preserved may be application-dependent.
]]> </xsl:template> </xsl:stylesheet></lang>
Output from xsltproc (input is ignored):
This text is in a CDATA section. In here, it's okay to include <, >, &, ", and '
without any special treatment.
The section is terminated by a three-character sequence consisting of two right
brackets ("]]") followed by a greater-than (">"). If this sequence appears in
your text, a workaround is to drop out of the CDATA section, output part of the
terminator, then start a new CDATA section and output the rest. Let's do this
now:
]]>
Newlines and spacing are retained as well, as long as they're evaluated in a
context that bothers preserving them. Whether or not the spaces before and after
the CDATA section are also preserved may be application-dependent.
zkl
<lang zkl>x:=
- <<<
"#<<< starts a block of lines that are concatenated verbatim and fed into the parser as one line. #<<< ends the block. Both #<<< tokens must start the line that is otherwise ignored
Note that is isn't a string, but arbitrary source " + 1 + 23;
- <<<
x.println();</lang>
- Output:
#<<< starts a block of lines that are concatenated verbatim and fed into the parser as one line. #<<< ends the block. Both #<<< tokens must start the line that is otherwise ignored Note that is isn't a string, but arbitrary source 123