Append a record to the end of a text file: Difference between revisions

imported>Regattaguru
 
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Alternatively: If the language's appends can not guarantee its writes will '''always''' append, then note this restriction in the table. If possible, provide an actual code example (possibly using file/record locking) to guarantee correct concurrent appends.
<br><br>
 
=={{header|Action!}}==
<syntaxhighlight lang="action!">PROC CreateLog(CHAR ARRAY fname)
CHAR ARRAY header="account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell"
BYTE dev=[1]
 
Close(dev)
Open(dev,fname,8)
PrintDE(dev,header)
Close(dev)
RETURN
 
PROC AppendLog(CHAR ARRAY fname,line)
BYTE dev=[1]
 
Close(dev)
Open(dev,fname,9)
PrintDE(dev,line)
Close(dev)
RETURN
 
PROC ReadFile(CHAR ARRAY fname)
CHAR ARRAY line(255)
BYTE dev=[1]
 
Close(dev)
Open(dev,fname,4)
WHILE Eof(dev)=0
DO
InputSD(dev,line)
IF line(0) THEN
PutE() Print(line)
FI
OD
Close(dev)
RETURN
 
PROC PrintInv(CHAR ARRAY a)
BYTE i
 
IF a(0)>0 THEN
FOR i=1 TO a(0)
DO
Put(a(i)%$80)
OD
FI
RETURN
 
PROC Main()
CHAR ARRAY fname="D:PASSWD"
BYTE LMARGIN=$52,oldLMARGIN
 
oldLMARGIN=LMARGIN
LMARGIN=0 ;remove left margin on the screen
Put(125) PutE() ;clear the screen
 
CreateLog(fname)
AppendLog(fname,"jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash")
AppendLog(fname,"jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash")
 
PrintInv("Initial log:")
ReadFile(fname)
 
AppendLog(fname,"xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash")
PutE() PrintInv("Updated log:")
ReadFile(fname)
 
LMARGIN=oldLMARGIN ;restore left margin on the screen
RETURN</syntaxhighlight>
{{out}}
[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Append_a_record_to_the_end_of_a_text_file.png Screenshot from Atari 8-bit computer]
<pre>
Initial log:
account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
 
Updated log:
account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash
</pre>
 
=={{header|Ada}}==
<syntaxhighlight lang="ada">
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
with Ada.Strings.Bounded;
 
procedure Main is
package data_string is new Ada.Strings.Bounded.Generic_Bounded_Length(80);
use data_string;
type GCOSE_Rec is record
Full_Name : Bounded_String;
Office : Bounded_String;
Extension : Bounded_String;
Homephone : Bounded_String;
Email : Bounded_String;
end record;
type Password_Rec is record
Account : Bounded_String;
Password : Bounded_String;
Uid : Natural;
Gid : Natural;
GCOSE : GCOSE_Rec;
Directory : Bounded_String;
Shell : Bounded_String;
end record;
function To_String(Item : GCOSE_Rec) return String is
begin
return To_String(Item.Full_Name) & "," &
To_String(Item.Office) & "," &
To_String(Item.Extension) & "," &
To_String(Item.Homephone) & "," &
To_String(Item.Email);
end To_String;
function To_String(Item : Password_Rec) return String is
uid_str : string(1..4);
gid_str : string(1..4);
Temp : String(1..5);
begin
Temp := Item.Uid'Image;
uid_str := Temp(2..5);
Temp := Item.Gid'Image;
gid_str := Temp(2..5);
return To_String(Item.Account) & ":" &
To_String(Item.Password) & ":" &
uid_str & ":" & gid_str & ":" &
To_String(Item.GCOSE) & ":" &
To_String(Item.Directory) & ":" &
To_String(Item.Shell);
end To_String;
Pwd_List : array (1..3) of Password_Rec;
Filename : String := "password.txt";
The_File : File_Type;
Line : String(1..256);
Length : Natural;
begin
Pwd_List(1) := (Account => To_Bounded_String("jsmith"),
Password => To_Bounded_String("x"),
Uid => 1001, GID => 1000,
GCOSE => (Full_Name => To_Bounded_String("Joe Smith"),
Office => To_Bounded_String("Room 1007"),
Extension => To_Bounded_String("(234)555-8917"),
Homephone => To_Bounded_String("(234)555-0077"),
email => To_Bounded_String("jsmith@rosettacode.org")),
directory => To_Bounded_String("/home/jsmith"),
shell => To_Bounded_String("/bin/bash"));
Pwd_List(2) := (Account => To_Bounded_String("jdoe"),
Password => To_Bounded_String("x"),
Uid => 1002, GID => 1000,
GCOSE => (Full_Name => To_Bounded_String("Jane Doe"),
Office => To_Bounded_String("Room 1004"),
Extension => To_Bounded_String("(234)555-8914"),
Homephone => To_Bounded_String("(234)555-0044"),
email => To_Bounded_String("jdoe@rosettacode.org")),
directory => To_Bounded_String("/home/jdoe"),
shell => To_Bounded_String("/bin/bash"));
Pwd_List(3) := (Account => To_Bounded_String("xyz"),
Password => To_Bounded_String("x"),
Uid => 1003, GID => 1000,
GCOSE => (Full_Name => To_Bounded_String("X Yz"),
Office => To_Bounded_String("Room 1003"),
Extension => To_Bounded_String("(234)555-8913"),
Homephone => To_Bounded_String("(234)555-0033"),
email => To_Bounded_String("xyz@rosettacode.org")),
directory => To_Bounded_String("/home/xyz"),
shell => To_Bounded_String("/bin/bash"));
Create(File => The_File,
Mode => Out_File,
Name => Filename);
for I in 1..2 loop
Put_Line(File => The_File,
Item => To_String(Pwd_List(I)));
end loop;
Reset(File => The_File,
Mode => In_File);
while not End_Of_File(The_File) loop
Get_Line(File => The_File,
Item => Line,
Last => Length);
Put_Line(Line(1..Length));
end loop;
New_Line;
Reset(File => The_File,
Mode => Append_File);
Put_Line(File => The_File,
Item => To_String(Pwd_List(3)));
Reset(File => The_File,
Mode => In_File);
while not End_Of_File(The_File) loop
Get_Line(File => The_File,
Item => Line,
Last => Length);
Put_Line(Line(1..Length));
end loop;
Close(The_File);
end Main;
</syntaxhighlight>
{{output}}
<pre>
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
 
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash
</pre>
 
=={{header|AWK}}==
<syntaxhighlight lang="awk">
<lang AWK>
# syntax: GAWK -f APPEND_A_RECORD_TO_THE_END_OF_A_TEXT_FILE.AWK
BEGIN {
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printf("%d records\n\n",nr)
}
</syntaxhighlight>
</lang>
<p>Output:</p>
<pre>
Line 105 ⟶ 322:
 
=={{header|Batch File}}==
<langsyntaxhighlight lang="dos">
@echo off
 
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type append.txt
pause>nul
</syntaxhighlight>
</lang>
 
{{out}}
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'''From a C "struct" to CSV File'''
<langsyntaxhighlight Clang="c">#include <stdio.h>
#include <string.h>
/* note that UID & GID are of type "int" */
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if(strstr(passwd_buf, "xyz"))
printf("Appended record: %s\n", passwd_buf);
}</langsyntaxhighlight>
{{out}}
<pre>
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=={{header|C sharp|C#}}==
<langsyntaxhighlight lang="csharp">using System;
using System.IO;
 
Line 255 ⟶ 472:
}
}
</syntaxhighlight>
</lang>
 
{{out}}
Line 263 ⟶ 480:
=={{header|C++}}==
{{trans|C#}}
<langsyntaxhighlight lang="cpp">#include <iostream>
#include <fstream>
#include <string>
Line 343 ⟶ 560:
 
return 0;
}</langsyntaxhighlight>
{{out}}
<pre>Appended record: xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
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'''Record group to passwd format, LINE SEQUENTIAL'''
<syntaxhighlight lang="cobol">
<lang COBOL>
*> Tectonics:
*> cobc -xj append.cob
Line 666 ⟶ 883:
.
 
end program append.</langsyntaxhighlight>
{{out}}
<pre>prompt$ cobc -xj append.cob
Line 674 ⟶ 891:
=={{header|Common Lisp}}==
Tested on CLISP 2.49
<langsyntaxhighlight lang="lisp">(defvar *initial_data*
(list
(list "jsmith" "x" 1001 1000
Line 726 ⟶ 943:
 
(main)
</syntaxhighlight>
</lang>
{{out}}
<pre>$ clisp append_file.cl
Line 747 ⟶ 964:
=={{header|D}}==
{{trans|Java}}
<langsyntaxhighlight Dlang="d">class Record {
private const string account;
private const string password;
Line 839 ⟶ 1,056:
}
passwd.close();
}</langsyntaxhighlight>
 
{{out}}
Line 860 ⟶ 1,077:
| objects (subclass of Struct builtin) || text file || builtin || ☑ || ☑ || ☒
|}
<langsyntaxhighlight lang="elixir">
defmodule Gecos do
defstruct [:fullname, :office, :extension, :homephone, :email]
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Appender.write("passwd.txt")
</syntaxhighlight>
</lang>
{{out}}
<pre>
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In the absence of a length indication, when outputting text variables with a view to having them read in again, delimiting them with quotes (and doubling internal quotes) is the route to peace of mind, because otherwise a text might contain a comma as in "43 Gurney Road, Belmont" and in the absence of quoting, such a sequence on input might well be taken as two fields rather than one and a mess is certain. This facility is offered by the free-format (or, "list directed") style initiated by the use of * in place of a format label, as in <code>WRITE (MSG,*) ''etc.''</code>, provided however that the output file has been opened with the optional usage attribute <code>DELIM = "QUOTE"</code>, an unfortunate choice of name, because the field separator character could also be termed a "delimiter" and the default value is both a space or comma, when often what is preferable is only a comma, or even a tab. But there is no standard method to specify this desire. Only if the texts never themselves contain commas or spaces will this unquoted free-format scheme evade extra effort, and the specified example precludes this simplicity.
 
The resulting output is strung along an output line, with a default line length of 132 (a standard lineprinter width); the specification of RECL = 666 ensures that all the output fields are rolled to one line - that isn't padded out to 666 characters: this is not a fixed-length record despite the specification of RECL as a constant, though each record turns out to be 248 characters long. Unfortunately, the trailing spaces in each character variable are rolled forth and there is no option along the lines of <code>WRITE (MSG,*) TRIM(NOTE)</code> One could instead use a suitable FORMAT statement with "A" format codes, but every element of NOTE would have to be named in the output list and the TRIM function applied only to each character field. Not only would this be tedious and error-prone, there is no format code for the enquoting and double-quoting of the texts and thus, no peace of mind... One would of course devise a subroutine to write out such a record (which would probably be more complex, with the FULLNAME subdivided, etc.), but the task's main objective is to demonstrate appending output to a file.<langsyntaxhighlight Fortranlang="fortran"> PROGRAM DEMO !As per the described task, more or less.
TYPE DETAILS !Define a component.
CHARACTER*28 FULLNAME
Line 1,023 ⟶ 1,240:
Closedown.
20 CLOSE (F)
END</langsyntaxhighlight>
 
The output can be read back in with the same free-format style. The fields are separated by spaces (outside a quoted string) though commas are also allowed. The file content is as follows:
Line 1,085 ⟶ 1,302:
 
=={{header|FreeBASIC}}==
<langsyntaxhighlight lang="freebasic">' FB 1.05.0 Win64
 
Type Person
Line 1,170 ⟶ 1,387:
Open "passwd.txt" For Append Lock Write As #1
Print #1, records(3)
Close #1</langsyntaxhighlight>
 
{{out}}
Line 1,194 ⟶ 1,411:
| FB Type || CSV text file || FB Standard Library || ☑ || ☑ || ☑ (Hopefully!)
|}
 
=={{header|Free Pascal}}==
''See also [[#Pascal|Pascal]]''
{{works with|Linux}}
<syntaxhighlight lang="delphi">{$mode objFPC}
{$longStrings on}
{$modeSwitch classicProcVars+}
 
uses
cTypes,
// for system call wrappers
unix;
 
const
passwdPath = '/tmp/passwd';
 
resourceString
advisoryLockFailed = 'Error: could not obtain advisory lock';
 
type
GECOS = object
fullname: string;
office: string;
extension: string;
homephone: string;
email: string;
function asString: string;
end;
entry = object
account: string;
password: string;
UID: cUInt;
GID: cUInt;
comment: GECOS;
directory: string;
shell: string;
function asString: string;
end;
 
function GECOS.asString: string;
const
separator = ',';
begin
with self do
begin
writeStr(result, fullname, separator, office, separator, extension,
separator, homephone, separator, email);
end;
end;
 
function entry.asString: string;
const
separator = ':';
begin
with self do
begin
writeStr(result, account, separator, password, separator, UID:1,
separator, GID:1, separator, comment.asString, separator, directory,
separator, shell);
end;
end;
procedure writeEntry(var f: text; const value: entry);
begin
writeLn(f, value.asString);
end;
 
procedure appendEntry(var f: text; const value: entry);
begin
// (re-)open for writing and immediately seek to EOF
append(f);
writeEntry(f, value);
end;
 
 
// === MAIN ==============================================================
var
passwd: text;
 
procedure releaseLock;
begin
// equivalent to `exitCode := exitCode + …`
inc(exitCode, fpFLock(passwd, lock_un));
end;
 
var
user: entry;
line: string;
 
begin
assign(passwd, passwdPath);
// open for reading
reset(passwd);
if fpFLock(passwd, lock_ex or lock_NB) <> 0 then
begin
writeLn(stdErr, advisoryLockFailed);
halt(1);
end;
addExitProc(releaseLock);
// reopen for _over_writing: immediately sets file size to 0
rewrite(passwd);
user.account := 'jsmith';
user.password := 'x';
user.UID := 1001;
user.GID := 1000;
user.comment.fullname := 'Joe Smith';
user.comment.office := 'Room 1007';
user.comment.extension := '(234)555-8917';
user.comment.homephone := '(234)555-0077';
user.comment.email := 'jsmith@rosettacode.org';
user.directory := '/home/jsmith';
user.shell := '/bin/bash';
appendEntry(passwd, user);
with user do
begin
account := 'jdoe';
password := 'x';
UID := 1002;
GID := 1000;
with comment do
begin
fullname := 'Jane Doe';
office := 'Room 1004';
extension := '(234)555-8914';
homephone := '(234)555-0044';
email := 'jdoe@rosettacode.org';
end;
directory := '/home/jdoe';
shell := '/bin/bash';
end;
appendEntry(passwd, user);
// Close the file, ...
close(passwd);
with user, user.comment do
begin
account := 'xyz';
UID := 1003;
fullname := 'X Yz';
office := 'Room 1003';
extension := '(234)555-8913';
homephone := '(234)555-0033';
email := 'xyz@rosettacode.org';
directory := '/home/xyz';
end;
// ... then reopen the file for append.
appendEntry(passwd, user);
// open the file and demonstrate the new record has indeed written to the end
reset(passwd);
while not EOF(passwd) do
begin
readLn(passwd, line);
writeLn(line);
end;
end.</syntaxhighlight>
{{out}}
<pre>jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
 
{| class="wikitable" style="text-align: center; margin: 1em auto;"
|+ Append Capabilities.
|-
! colspan="2" | Data Representation
! rowspan="2" | IO<br/>Library
! rowspan="2" | Append<br/>Possible
! rowspan="2" | Automatic<br/>Append
! rowspan="2" | Multi-tasking<br/>Safe
|-
! In core || On disk
|-
| <tt>record</tt> || ASCII text || default <abbr title="run-time library">RTL</abbr> || ☑ || ☐ || ☐
|}
 
=={{header|FutureBasic}}==
<syntaxhighlight lang="futurebasic">
local fn AppendRecordToFile( pwStr as CFStringRef, url as CFURLRef ) as BOOL
ErrorRef err = NULL
BOOL success = YES
CFDataRef pwData = fn StringData( pwStr, NSUTF8StringEncoding )
FileHandleRef fh = fn FileHandleForWritingToURL( url, @err )
if ( err )
success = fn FileManagerFileExistsAtURL( url )
if success == NO then fn FileManagerCreateFileAtURL( url, pwData, NULL ) : success = YES : exit fn
end if
success = fn FileHandleSeekToEnd( fh, NULL, @err )
if success == NO then print fn ErrorLocalizedDescription( err ) : exit fn
success = fn FileHandleWriteData( fh, pwData, @err )
if success == NO then print fn ErrorLocalizedDescription( err ) : exit fn
success = fn FileHandleClose( fh, @err )
if success == NO then print fn ErrorLocalizedDescription( err ) : exit fn
end fn = success
 
local fn ReadFileRecords( url as CFURLRef )
ErrorRef err = NULL
CFDataRef pwData = fn DataWithContentsOfURL( url, NSDataReadingMappedIfSafe, @err )
if err then print fn ErrorLocalizedDescription( err ) : exit fn
print fn StringWithData( pwData, NSUTF8StringEncoding )
end fn
 
local fn ProcessRecords
BOOL success = NO
CFURLRef desktopURL = fn FileManagerURLForDirectory( NSDesktopDirectory, NSUserDomainMask )
CFURLRef url = fn URLByAppendingPathComponent( desktopURL, @"passwords.txt" )
CFArrayRef pwRecords = @[@"account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell\n",¬
@"jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash\n",¬
@"jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash\n"]
NSUInteger i, count = len(pwRecords)
for i = 0 to count - 1
success = fn AppendRecordToFile( pwRecords[i], url )
if success then printf @"Record appended to file." else printf @"Failed to append record."
next
fn ReadFileRecords( url )
end fn
 
fn ProcessRecords
 
HandleEvents
</syntaxhighlight>
{{output}}
<pre>
Record appended to file.
Record appended to file.
Record appended to file.
account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
 
</pre>
 
 
=={{header|Go}}==
<langsyntaxhighlight lang="go">package main
 
import (
Line 1,296 ⟶ 1,753:
fmt.Println("it didn't work")
}
}</langsyntaxhighlight>
{{out}}
<pre>
Line 1,324 ⟶ 1,781:
=={{header|Groovy}}==
Solution:
<langsyntaxhighlight lang="groovy">class PasswdRecord {
String account, password, directory, shell
int uid, gid
Line 1,391 ⟶ 1,848:
w.append('\r\n')
}
}</langsyntaxhighlight>
 
Test:
<langsyntaxhighlight lang="groovy">def checkPasswdFile = { it ->
File passwd = new File('passwd.txt')
assert passwd.exists()
Line 1,414 ⟶ 1,871:
 
println "File contents after new record added"
checkPasswdFile()</langsyntaxhighlight>
 
Output:
Line 1,428 ⟶ 1,885:
=={{header|Haskell}}==
Solution:
<langsyntaxhighlight lang="haskell">
{-# LANGUAGE RecordWildCards #-}
 
Line 1,458 ⟶ 1,915:
addRecord :: String -> Record -> IO ()
addRecord path r = appendFile path (show r)
</syntaxhighlight>
</lang>
 
Test:
<langsyntaxhighlight lang="haskell">
t1 = Record "jsmith" "x" 1001 1000 "/home/jsmith" "/bin/bash"
(Gecos "Joe Smith" "Room 1007" "(234)555-8917" "(234)555-0077" "jsmith@rosettacode.org")
Line 1,476 ⟶ 1,933:
lastLine <- fmap (last . lines) (readFile path)
putStrLn lastLine
</syntaxhighlight>
</lang>
 
=={{header|Icon}} and {{header|Unicon}}==
Works in both languages:
<langsyntaxhighlight lang="unicon">procedure main()
orig := [
"jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash",
Line 1,492 ⟶ 1,949:
every (f := open(fName,"a")) | write(f,!new) | close(f)
every (f := open(fName,"r")) | write(!f) | close(f)
end</langsyntaxhighlight>
 
Run:
Line 1,517 ⟶ 1,974:
 
=={{header|J}}==
<langsyntaxhighlight lang="j">require'strings ~system/packages/misc/xenos.ijs'
record=: [:|: <@deb;._1@(':',]);._2@do bind '0 :0'
 
Line 1,559 ⟶ 2,016:
R3 fappend passwd
 
assert 1 e. R3 E. fread passwd </langsyntaxhighlight>
 
{|class="wikitable" style="text-align: center; margin: 1em auto 1em auto;"
Line 1,574 ⟶ 2,031:
 
=={{header|Java}}==
<syntaxhighlight lang="java">
 
<lang java>import static java.util.Objectsio.requireNonNullFileOutputStream;
import java.io.IOException;
</syntaxhighlight>
<syntaxhighlight lang="java">
void append(String path, byte[] data) throws IOException {
/* the second argument here is for appending bytes */
try (FileOutputStream output = new FileOutputStream(path, true)) {
output.write(data);
}
}
</syntaxhighlight>
<br />
An alternate implementation.
<syntaxhighlight lang="java">import static java.util.Objects.requireNonNull;
 
import java.io.IOException;
Line 1,645 ⟶ 2,115:
}
}
}</langsyntaxhighlight>
{{out}}
<pre>Appended Record: xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
 
=={{header|Julia}}==
<langsyntaxhighlight lang="julia">
using SHA # security instincts say do not write bare passwords to a shared file even in toy code :)
 
Line 1,697 ⟶ 2,167:
writepasswd(pfile, xyz)
println("After last record added, file is:\n$(readstring(pfile))")
</syntaxhighlight>
</lang>
{{output}}<pre>
Before last record added, file is:
Line 1,711 ⟶ 2,181:
=={{header|Kotlin}}==
{{works with|Ubuntu 16.04}}
<langsyntaxhighlight lang="scala">// Version 1.2.41
 
import java.io.File
Line 1,766 ⟶ 2,236:
println(parseRecord(it))
}
}</langsyntaxhighlight>
 
{{output}}
Line 1,797 ⟶ 2,267:
 
=={{header|Lua}}==
<langsyntaxhighlight lang="lua">function append(tbl,filename)
local file,err = io.open(filename, "a")
if err then return err end
Line 1,848 ⟶ 2,318:
xyz.directory = "/home/xyz"
xyz.shell = "/bin/bash"
append(xyz, ".passwd")</langsyntaxhighlight>
=={{header|M2000 Interpreter}}==
<langsyntaxhighlight M2000lang="m2000 Interpreterinterpreter">Module TestThis {
Class passwd {
account$, password$
Line 1,930 ⟶ 2,400:
}
TestThis
</syntaxhighlight>
</lang>
{{out}}
<pre>
Line 1,939 ⟶ 2,409:
 
=={{header|Mathematica}} / {{header|Wolfram Language}}==
<langsyntaxhighlight Mathematicalang="mathematica">data = <|"account" -> "xyz", "password" -> "x", "UID" -> 1003,
"GID" -> 1000, "fullname" -> "X Yz", "office" -> "Room 1003",
"extension" -> "(234)555-8913", "homephone" -> "(234)555-0033",
Line 1,955 ⟶ 2,425:
str = OpenWrite[fname]; (* Use OpenAppend if file exists *)
Close[str];
Print["Appended record: " <> asString[data]];</langsyntaxhighlight>
{{out}}
<pre>Appended record: xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
Line 1,973 ⟶ 2,443:
 
=={{header|MATLAB}} / {{header|Octave}}==
<langsyntaxhighlight Matlablang="matlab"> DS{1}.account='jsmith';
DS{1}.password='x';
DS{1}.UID=1001;
Line 2,030 ⟶ 2,500:
printf('%s\n',fgetl(fid));
end;
fclose(fid); </langsyntaxhighlight>
{{out}}
<pre>jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith/bin/bash
Line 2,036 ⟶ 2,506:
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz/bin/bash
</pre>
 
=={{header|Nim}}==
This solution defines a procedure "getlock" which try the get an exclusive (write) lock on the file. On Posix systems, the standard Posix advisory locking mechanism, which works at process level, is used. On other systems, especially Windows, the procedure does nothing and returns true as there is no need for such a mechanism.
 
 
Note that on Posix system, other programs may still write on the file if they do not check if an exclusive lock is already set on the file.
 
 
As several other solutions, we have chosen to parse the "passwd" lines even if it not required.
<syntaxhighlight lang="nim">import posix
import strutils
 
type
 
# GECOS representation.
Gecos = tuple[fullname, office, extension, homephone, email: string]
 
# Record representation.
Record = object
account: string
password: string
uid: int
gid: int
gecos: Gecos
directory: string
shell: string
 
#---------------------------------------------------------------------------------------------------
 
proc str(gecos: Gecos): string =
## Explicit representation of a GECOS.
 
result = "("
for name, field in gecos.fieldPairs:
result.addSep(", ", 1)
result.add(name & ": " & field)
result.add(')')
 
#---------------------------------------------------------------------------------------------------
 
proc `$`(gecos: Gecos): string =
## Compact representation of a GECOS.
 
for field in gecos.fields:
result.addSep(",", 0)
result.add(field)
 
#---------------------------------------------------------------------------------------------------
 
proc parseGecos(s: string): Gecos =
## Parse a string and return a Gecos tuple.
 
let fields = s.split(",")
result = (fields[0], fields[1], fields[2], fields[3], fields[4])
 
#---------------------------------------------------------------------------------------------------
 
proc str(rec: Record): string =
## Explicit representation of a record.
 
for name, field in rec.fieldPairs:
result.add(name & ": ")
when typeof(field) is Gecos:
result.add(str(field))
else:
result.add($field)
result.add('\n')
 
#---------------------------------------------------------------------------------------------------
 
proc `$`(rec: Record): string =
# Compact representation fo a record.
 
for field in rec.fields:
result.addSep(":", 0)
result.add($field)
 
#---------------------------------------------------------------------------------------------------
 
proc parseRecord(line: string): Record =
## Parse a string and return a Record object.
 
let fields = line.split(":")
result.account = fields[0]
result.password = fields[1]
result.uid = fields[2].parseInt()
result.gid = fields[3].parseInt()
result.gecos = parseGecos(fields[4])
result.directory = fields[5]
result.shell = fields[6]
 
#---------------------------------------------------------------------------------------------------
 
proc getLock(f: File): bool =
## Try to get an exclusive write lock on file "f". Return false is unsuccessful.
 
when defined(posix):
var flock = TFlock(l_type: cshort(F_WRLCK), l_whence: cshort(SEEK_SET), l_start: 0, l_len: 0)
result = f.getFileHandle().fcntl(F_SETLK, flock.addr) >= 0
else:
result = true
 
#———————————————————————————————————————————————————————————————————————————————————————————————————
 
var pwfile: File
 
const Filename = "passwd"
 
const Data = ["jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash",
"jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash"]
 
# Prepare initial file.
# We don'’t use a lock here as it is only the preparation.
pwfile = open(FileName, fmWrite)
for line in Data:
pwfile.writeLine(line)
pwfile.close()
 
# Display initial contents.
echo "Raw content of initial password file:"
echo "-------------------------------------"
var records: seq[Record]
for line in lines(FileName):
echo line
records.add(line.parseRecord())
 
echo ""
echo "Structured content of initial password file:"
echo "--------------------------------------------"
for rec in records:
echo str(rec)
 
# Add a new record at the end of password file.
pwfile = open(Filename, fmAppend)
let newRecord = Record(account: "xyz",
password: "x",
uid: 1003,
gid: 1000,
gecos: ("X Yz", "Room 1003", "(234)555-8913", "(234)555-0033", "xyz@rosettacode.org"),
directory: "/home/xyz",
shell: "/bin/bash")
echo "Appending new record:"
echo "---------------------"
echo str(newRecord)
if pwfile.getLock():
pwFile.writeLine(newRecord)
pwfile.close()
else:
echo "File is locked. Quitting."
pwFile.close()
quit(QuitFailure)
 
# Reopen the file and display its contents.
echo "Raw content of updated password file:"
echo "-------------------------------------"
for line in lines(FileName):
echo line</syntaxhighlight>
 
{{out}}
<pre>Raw content of initial password file:
-------------------------------------
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
 
Structured content of initial password file:
--------------------------------------------
account: jsmith
password: x
uid: 1001
gid: 1000
gecos: (fullname: Joe Smith, office: Room 1007, extension: (234)555-8917, homephone: (234)555-0077, email: jsmith@rosettacode.org)
directory: /home/jsmith
shell: /bin/bash
 
account: jdoe
password: x
uid: 1002
gid: 1000
gecos: (fullname: Jane Doe, office: Room 1004, extension: (234)555-8914, homephone: (234)555-0044, email: jdoe@rosettacode.org)
directory: /home/jdoe
shell: /bin/bash
 
Appending new record:
---------------------
account: xyz
password: x
uid: 1003
gid: 1000
gecos: (fullname: X Yz, office: Room 1003, extension: (234)555-8913, homephone: (234)555-0033, email: xyz@rosettacode.org)
directory: /home/xyz
shell: /bin/bash
 
Raw content of updated password file:
-------------------------------------
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
 
{|class="wikitable" style="text-align: center; margin: 1em auto 1em auto;"
|+ Append Capabilities.
|-
!colspan=2| Data Representation
!rowspan=2| IO<BR>Library
!rowspan=2| Append<BR>Possible
!rowspan=2| Automatic<BR>Append
!rowspan=2| Multi-tasking<BR>Safe
|-
! In core || On disk
|-
| Object/Tuple || Text file || Nim Io || ☑ || ☑ || Window: yes<br/>Posix: Advisory lock
|}
 
=={{header|Pascal}}==
''See also: [[#Free Pascal|Free Pascal]]''
{{works with|Extended Pascal}}
<syntaxhighlight lang="pascal">program appendARecordToTheEndOfATextFile;
 
var
passwd: bindable text;
FD: bindingType;
 
begin
{ initialize FD }
FD := binding(passwd);
FD.name := '/tmp/passwd';
{ attempt opening file [e.g. effective user has proper privileges?] }
bind(passwd, FD);
{ query binding state of `passwd` }
FD := binding(passwd);
if not FD.bound then
begin
writeLn('Error: could not open ', FD.name);
halt;
end;
{ open for overwriting }
rewrite(passwd);
writeLn(passwd, 'jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash');
writeLn(passwd, 'jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash');
{ close }
unbind(passwd);
{ rebind }
bind(passwd, FD);
FD := binding(passwd);
if not FD.bound then
begin
writeLn('Error: could not reopen ', FD.name);
halt;
end;
{ open in append/writable mode }
extend(passwd);
{ write another record to file }
writeLn(passwd, 'xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash');
end.</syntaxhighlight>
 
{| class="wikitable" style="text-align: center; margin: 1em auto;"
|+ Append Capabilities.
|-
! colspan="2" | Data Representation
! rowspan="2" | IO<br/>Library
! rowspan="2" | Append<br/>Possible
! rowspan="2" | Automatic<br/>Append
! rowspan="2" | Multi-tasking<br/>Safe
|-
! In core || On disk
|-
| string literal || ASCII text || language core || ☑ || ☐ || ☐
|}
 
=={{header|Perl}}==
The program uses flock(2) (or emulation, if flock is not available) to lock the file.
<langsyntaxhighlight Perllang="perl">use strict;
use warnings;
 
Line 2,145 ⟶ 2,891:
);
}
</syntaxhighlight>
</lang>
 
Output:
Line 2,192 ⟶ 2,938:
same process, in which case locking does not make any real difference - because there is no task_yield() in a locked state.
You can also test the locking when running multiple processes/threads by uncommenting the wait_key() lines.
<!--<syntaxhighlight lang="phix">(notonline)-->
<lang Phix>constant filename = "passwd.txt"
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (file i/o, sleep, task_yield, wait_key)</span>
integer fn
<span style="color: #008080;">constant</span> <span style="color: #000000;">filename</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"passwd.txt"</span>
 
<span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span>
constant
rec1 = {"jsmith","x",1001,1000,{"Joe Smith","Room 1007","(234)555-8917","(234)555-0077","jsmith@rosettacode.org"},"/home/jsmith","/bin/bash"},
<span style="color: #008080;">constant</span>
rec2 = {"jdoe","x",1002,1000,{"Jane Doe","Room 1004","(234)555-8914","(234)555-0044","jdoe@rosettacode.org"},"/home/jdoe","/bin/bash"},
<span style="color: #000000;">rec1</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"jsmith"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"x"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1001</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"Joe Smith"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Room 1007"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(234)555-8917"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(234)555-0077"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"jsmith@rosettacode.org"</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"/home/jsmith"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"/bin/bash"</span><span style="color: #0000FF;">},</span>
rec3 = {"xyz","x",1003,1000,{"X Yz","Room 1003","(234)555-8913","(234)555-0033","xyz@rosettacode.org"},"/home/xyz","/bin/bash"}
<span style="color: #000000;">rec2</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"jdoe"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"x"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1002</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"Jane Doe"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Room 1004"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(234)555-8914"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(234)555-0044"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"jdoe@rosettacode.org"</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"/home/jdoe"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"/bin/bash"</span><span style="color: #0000FF;">},</span>
 
<span style="color: #000000;">rec3</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"xyz"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"x"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1003</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"X Yz"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Room 1003"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(234)555-8913"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(234)555-0033"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"xyz@rosettacode.org"</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"/home/xyz"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"/bin/bash"</span><span style="color: #0000FF;">}</span>
function tostring(sequence record)
record[3] = sprintf("%d",{record[3]})
<span style="color: #008080;">function</span> <span style="color: #000000;">tostring</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">record</span><span style="color: #0000FF;">)</span>
record[4] = sprintf("%d",{record[4]})
<span style="color: #000000;">record</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%d"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">record</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">]})</span>
record[5] = join(record[5],",")
<span style="color: #000000;">record</span><span style="color: #0000FF;">[</span><span style="color: #000000;">4</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%d"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">record</span><span style="color: #0000FF;">[</span><span style="color: #000000;">4</span><span style="color: #0000FF;">]})</span>
record = join(record,":")
<span style="color: #000000;">record</span><span style="color: #0000FF;">[</span><span style="color: #000000;">5</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">record</span><span style="color: #0000FF;">[</span><span style="color: #000000;">5</span><span style="color: #0000FF;">],</span><span style="color: #008000;">","</span><span style="color: #0000FF;">)</span>
return record
<span style="color: #000000;">record</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">record</span><span style="color: #0000FF;">,</span><span style="color: #008000;">":"</span><span style="color: #0000FF;">)</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">record</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
procedure wait(string what)
?sprintf("wait (%s)",{what})
<span style="color: #008080;">procedure</span> <span style="color: #000000;">wait</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">what</span><span style="color: #0000FF;">)</span>
sleep(1)
<span style="color: #0000FF;">?</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"wait (%s)"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">what</span><span style="color: #0000FF;">})</span>
task_yield()
<span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
end procedure
<span style="color: #000000;">task_yield</span><span style="color: #0000FF;">()</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
if not file_exists(filename) then
fn = open(filename,"w")
<span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">file_exists</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
if fn!=-1 then -- (someone else just beat us to it?)
<span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"w"</span><span style="color: #0000FF;">)</span>
printf(fn,"account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell\n")
<span style="color: #008080;">if</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">!=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span> <span style="color: #000080;font-style:italic;">-- (someone else just beat us to it?)</span>
printf(fn,"%s\n",{tostring(rec1)})
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"account:password:UID:GID:fullname,office,extension,homephone,email:directory:shell\n"</span><span style="color: #0000FF;">)</span>
printf(fn,"%s\n",{tostring(rec2)})
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tostring</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rec1</span><span style="color: #0000FF;">)})</span>
close(fn)
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tostring</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rec2</span><span style="color: #0000FF;">)})</span>
end if
<span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
end if
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
while 1 do
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
fn = open(filename,"a")
<span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
if fn!=-1 then exit end if
<span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"a"</span><span style="color: #0000FF;">)</span>
wait("append")
<span style="color: #008080;">if</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">!=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end while
<span style="color: #000000;">wait</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"append"</span><span style="color: #0000FF;">)</span>
-- ?"file open in append mode"; {} = wait_key()
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
while 1 do
<span style="color: #000080;font-style:italic;">--?"file open in append mode"; {} = wait_key()</span>
if lock_file(fn,LOCK_EXCLUSIVE,{}) then exit end if
<span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
wait("lock")
<span style="color: #008080;">if</span> <span style="color: #000000;">lock_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">LOCK_EXCLUSIVE</span><span style="color: #0000FF;">,{})</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end while
<span style="color: #000000;">wait</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"lock"</span><span style="color: #0000FF;">)</span>
-- ?"file locked"; {} = wait_key()
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
printf(fn,"%s\n",{tostring(rec3)})
<span style="color: #000080;font-style:italic;">--?"file locked"; {} = wait_key()</span>
unlock_file(fn,{})
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tostring</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rec3</span><span style="color: #0000FF;">)})</span>
close(fn)
<span style="color: #000000;">unlock_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,{})</span>
while 1 do
<span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
fn = open(filename,"r")
<span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
if fn!=-1 then exit end if
<span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"r"</span><span style="color: #0000FF;">)</span>
wait("read")
<span style="color: #008080;">if</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">!=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end while
<span style="color: #000000;">wait</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"read"</span><span style="color: #0000FF;">)</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
?gets(fn)
while 1 do
<span style="color: #0000FF;">?</span><span style="color: #7060A8;">gets</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
object line = gets(fn)
<span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
if atom(line) then exit end if
<span style="color: #004080;">object</span> <span style="color: #000000;">line</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">gets</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
?line
<span style="color: #008080;">if</span> <span style="color: #004080;">atom</span><span style="color: #0000FF;">(</span><span style="color: #000000;">line</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
{line} = scanf(line,"%s:%s:%d:%d:%s:%s:%s\n")
<span style="color: #0000FF;">?</span><span style="color: #000000;">line</span>
line[5] = split(line[5],',')
<span style="color: #0000FF;">{</span><span style="color: #000000;">line</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">scanf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">line</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s:%s:%d:%d:%s:%s:%s\n"</span><span style="color: #0000FF;">)</span>
?line
<span style="color: #000000;">line</span><span style="color: #0000FF;">[</span><span style="color: #000000;">5</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">line</span><span style="color: #0000FF;">[</span><span style="color: #000000;">5</span><span style="color: #0000FF;">],</span><span style="color: #008000;">','</span><span style="color: #0000FF;">)</span>
end while
<span style="color: #0000FF;">?</span><span style="color: #000000;">line</span>
close(fn)</lang>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
Line 2,265 ⟶ 3,014:
 
=={{header|Phixmonti}}==
<langsyntaxhighlight Phixmontilang="phixmonti">include ..\Utilitys.pmt
 
def ltos /# l -- s #/
Line 2,320 ⟶ 3,069:
endif
endwhile
f fclose</langsyntaxhighlight>
{{out}}
<pre>["jsmith", "x", "1001", "1000", ["Joe Smith", "Room 1007", "(234)555-8917", "(234)555-0077", "jsmith@rosettacode.org"], "/home/jsmith", "/bin/bash"]
Line 2,344 ⟶ 3,093:
|}
 
<langsyntaxhighlight PHPlang="php"><?php
 
$filename = '/tmp/passwd';
Line 2,363 ⟶ 3,112:
 
echo 'File contents after new record added:', PHP_EOL, file_get_contents($filename), PHP_EOL;
</syntaxhighlight>
</lang>
 
{{out}}
Line 2,378 ⟶ 3,127:
 
=={{header|PicoLisp}}==
<langsyntaxhighlight PicoLisplang="picolisp">(setq L '((jsmith x 1001 1000
"Joe Smith,Room 1007,(234)555-8917,\
(234)555-0077,jsmith@rosettacode.org"
Line 2,404 ⟶ 3,153:
(= 3 (lines "mythical") ) ) ) )
 
(bye)</langsyntaxhighlight>
 
=={{header|PowerShell}}==
Line 2,410 ⟶ 3,159:
 
Since PowerShell loves to deal in objects I wrote extra code to better manipilate and display data.
<syntaxhighlight lang="powershell">
<lang PowerShell>
function Test-FileLock
{
Line 2,574 ⟶ 3,323:
}
}
</syntaxhighlight>
</lang>
Create record objects.
<syntaxhighlight lang="powershell">
<lang PowerShell>
$records = @()
 
Line 2,602 ⟶ 3,351:
-Directory '/home/jdoe' `
-Shell '/bin/bash'
</syntaxhighlight>
</lang>
Display record objects.
<syntaxhighlight lang="powershell">
<lang PowerShell>
$records | Format-Table -AutoSize
</syntaxhighlight>
</lang>
{{Out}}
<pre>
Line 2,615 ⟶ 3,364:
</pre>
Export records to file.
<syntaxhighlight lang="powershell">
<lang PowerShell>
if (-not(Test-FileLock -Path ".\passwd.txt"))
{
$records | Export-File -Path ".\passwd.txt"
}
</syntaxhighlight>
</lang>
This is the file.
<syntaxhighlight lang="powershell">
<lang PowerShell>
Get-Content -Path ".\passwd.txt"
</syntaxhighlight>
</lang>
{{Out}}
<pre>
Line 2,631 ⟶ 3,380:
</pre>
Add a record to the record set.
<syntaxhighlight lang="powershell">
<lang PowerShell>
$records+= New-Record -Account 'xyz' `
-Password 'x' `
Line 2,643 ⟶ 3,392:
-Directory '/home/xyz' `
-Shell '/bin/bash'
</syntaxhighlight>
</lang>
Display record objects, sorted on last name; and display them.
<syntaxhighlight lang="powershell">
<lang PowerShell>
$records | Sort-Object { $_.GECOS.FullName.Split(" ")[1] } | Format-Table -AutoSize
</syntaxhighlight>
</lang>
{{Out}}
<pre>
Line 2,657 ⟶ 3,406:
</pre>
Export records to file.
<syntaxhighlight lang="powershell">
<lang PowerShell>
if (-not(Test-FileLock -Path ".\passwd.txt"))
{
$records | Export-File -Path ".\passwd.txt"
}
</syntaxhighlight>
</lang>
This is the file.
<syntaxhighlight lang="powershell">
<lang PowerShell>
Get-Content -Path ".\passwd.txt"
</syntaxhighlight>
</lang>
{{Out}}
<pre>
Line 2,717 ⟶ 3,466:
|}
'''From a "dict" to a CSV File'''
<langsyntaxhighlight lang="python">#############################
# Create a passwd text file
#############################
Line 2,764 ⟶ 3,513:
passwd_list=list(open("passwd.txt","r"))
if "xyz" in passwd_list[-1]:
print "Appended record:",passwd_list[-1][:-1]</langsyntaxhighlight>
{{out}}
<pre>Appended record: xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
Line 2,786 ⟶ 3,535:
|}
 
<langsyntaxhighlight lang="racket">
#lang racket
 
Line 2,823 ⟶ 3,572:
 
(printf "Looking up xyz in current file:\n=> ~s\n" (lookup "xyz"))
</syntaxhighlight>
</lang>
 
{{out}}
Line 2,839 ⟶ 3,588:
This is kind of silly as it takes a string, converts it to a record, and then instantly converts it back to a string to write out to a file. Most of the "record handling" code is just demonstrating a possible way to store records in memory. It really has nothing to do with appending a string to a file.
 
<syntaxhighlight lang="raku" perl6line>class record {
has $.name;
has $.password;
Line 2,905 ⟶ 3,654:
put "Last line of $fname after append:";
put $fname.IO.lines.tail;
</syntaxhighlight>
</lang>
{{out}}
<pre>Last line of foo.fil before append:
Line 2,943 ⟶ 3,692:
|}
'''The easy short solution'''
<syntaxhighlight lang="vb">
<lang vb>
'Short solution: Append record and read last record
$Include "Rapidq.inc"
Line 2,972 ⟶ 3,721:
 
showmessage "Appended record: " + LogRec
</syntaxhighlight>
</lang>
{{out}}
<pre>Appended record: xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
 
'''Full solution: create an object to handle all functions'''
<syntaxhighlight lang="vb">
<lang vb>
'Full solution: Create an object with all required fields and
'build-in functions to append a record and to read the last record
Line 3,123 ⟶ 3,872:
Print ""
input "Press enter to exit:";a$
</syntaxhighlight>
</lang>
 
=={{header|REXX}}==
Line 3,141 ⟶ 3,890:
The data fields for the three records were coded on two statements instead of
<br>continuing them on separate statements for brevity.
<langsyntaxhighlight lang="rexx">/*REXX program writes (appends) two records, closes the file, appends another record.*/
tFID= 'PASSWD.TXT' /*define the name of the output file.*/
call lineout tFID /*close the output file, just in case,*/
Line 3,176 ⟶ 3,925:
 
say '***error***'; say r 'record's(r) "not written to file" fid; exit 13
/*some error causes: no write access, disk is full, file lockout, no authority*/</langsyntaxhighlight>
'''PASSWD.TXT''' file before the REXX program ran:
<pre>
Line 3,203 ⟶ 3,952:
| objects (subclass of Struct builtin) || text file || builtin || ☑ || ☑ || ☒
|}
<langsyntaxhighlight lang="ruby">Gecos = Struct.new :fullname, :office, :extension, :homephone, :email
class Gecos
def to_s
Line 3,238 ⟶ 3,987:
 
puts "after appending:"
puts File.readlines(filename)</langsyntaxhighlight>
{{out}}
<pre>
Line 3,251 ⟶ 4,000:
 
=={{header|Rust}}==
<langsyntaxhighlight lang="rust">
use std::fs::File;
use std::fs::OpenOptions;
Line 3,423 ⟶ 4,172:
}
}
</syntaxhighlight>
</lang>
{{out}}
<pre>
Line 3,437 ⟶ 4,186:
 
=={{header|Scala}}==
{{libheader|Scala}}<langsyntaxhighlight lang="scala">import java.io.{File, FileWriter, IOException}
import scala.io.Source
 
Line 3,492 ⟶ 4,241:
case e: IOException => println(s"Running Example failed: ${e.getMessage}")
}
} // 57 lines</langsyntaxhighlight>
=={{header|Scheme}}==
{{works with|Chez Scheme}}
<syntaxhighlight lang="scheme">; Join list of strings into single string, with given separator between elements.
(define string-join
(lambda (str-lst sep)
(fold-right (lambda (ele acc) (if (string=? acc "") ele (string-append ele sep acc)))
""
str-lst)))
 
; Define the output file name and the three records to write to it.
(let ((filename
"mimic-passwd.txt")
(record1
(string-join
(list
"jsmith" "x" "1001" "1000"
(string-join
'("Joe Smith" "Room 1007" "(234)555-8917" "(234)555-0077" "jsmith@rosettacode.org")
",")
"/home/jsmith" "/bin/bash")
":"))
(record2
(string-join
(list
"jdoe" "x" "1002" "1000"
(string-join
'("Jane Doe" "Room 1004" "(234)555-8914" "(234)555-0044" "jdoe@rosettacode.org")
",")
"/home/jdoe" "/bin/bash")
":"))
(record3
(string-join
(list
"xyz" "x" "1003" "1000"
(string-join
'("X Yz" "Room 1003" "(234)555-8913" "(234)555-0033" "xyz@rosettacode.org")
",")
"/home/xyz" "/bin/bash")
":")))
 
; Write the first two records to the output file.
; Replace any existing file. Lock file for exclusive access.
(let ((op (open-file-output-port filename
(file-options replace exclusive)
'line
(make-transcoder (latin-1-codec) 'lf))))
(format op "~a~%" record1)
(format op "~a~%" record2)
(close-output-port op))
 
; Append the third record to the output file.
; Open existing file keeping contents. Append to file. Lock file for exclusive access.
(let ((op (open-file-output-port filename
(file-options no-fail no-truncate append exclusive)
'line
(make-transcoder (latin-1-codec) 'lf))))
(format op "~a~%" record3)
(close-output-port op)))</syntaxhighlight>
{{out}}
<pre>
jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org:/home/jsmith:/bin/bash
jdoe:x:1002:1000:Jane Doe,Room 1004,(234)555-8914,(234)555-0044,jdoe@rosettacode.org:/home/jdoe:/bin/bash
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash
</pre>
{|class="wikitable" style="text-align: center; margin: 1em auto 1em auto;"
|+ Append Capabilities.
|-
!colspan=2| Data Representation
!rowspan=2| IO<BR>Library
!rowspan=2| Append<BR>Possible
!rowspan=2| Automatic<BR>Append
!rowspan=2| Multi-tasking<BR>Safe
|-
! In core || On disk
|-
| lists || text file || built-in || ☑ || ☑ || ☑ (system dependent)
|}
 
=={{header|Sidef}}==
Line 3,510 ⟶ 4,336:
|}
 
<langsyntaxhighlight lang="ruby">define (
RECORD_FIELDS = %w(account password UID GID GECOS directory shell),
GECOS_FIELDS = %w(fullname office extension homephone email),
Line 3,607 ⟶ 4,433:
'(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash')
 
say "** Test passed!"</langsyntaxhighlight>
 
Note that flock uses advisory lock; some other program (if it doesn't use flock) can still unexpectedly write to the file.
=={{header|Swift}}==
<syntaxhighlight lang="swift">
import Foundation
 
func appendPasswd(
account: String,
passwd: String,
uid: Int,
gid: Int,
bio: String,
home: String,
shell: String
) {
let str = [
account,
passwd,
String(uid),
String(gid),
bio,
home,
shell
].joined(separator: ":").appending("\n")
guard let data = str.data(using: .utf8) else { return }
let url = URL(fileURLWithPath: "./passwd")
do {
if let fileHandle = try? FileHandle(forWritingTo: url) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
try? fileHandle.close()
} else {
try data.write(to: url)
}
} catch {
print(error)
}
}
</syntaxhighlight>
Usage:
<syntaxhighlight lang="swift">
appendPasswd(
account: "jsmith",
passwd:"x",
uid: 1001,
gid: 1000,
bio: "Joe Smith,Room 1007,(234)555-8917,(234)555-0077,jsmith@rosettacode.org",
home: "/home/jsmith",
shell: "/bin/bash"
)
</syntaxhighlight>
 
=={{header|Tcl}}==
Line 3,626 ⟶ 4,501:
|}
Note that appending is only safe on POSIX OSes where the data is written in “small enough” amounts to a local disk. This is a limitation of the OS APIs.
<langsyntaxhighlight lang="tcl"># Model the data as nested lists, as that is a natural fit for Tcl
set basicRecords {
{
Line 3,710 ⟶ 4,585:
set recs [readRecords $f]
close $f
puts "last record is for [lindex $recs end 0], named [lindex $recs end 4 0]"</langsyntaxhighlight>{{out}}
last record is for xyz, named X Yz
The file will have this content:
Line 3,731 ⟶ 4,606:
| one-dimensional arrays (indexed or associative) || text file || builtin (shell redirections) || ☑ || ☑ || OS defined
|}
<langsyntaxhighlight lang="bash">rec1=(
jsmith
x
Line 3,779 ⟶ 4,654:
 
echo after appending:
cat "$filename"</langsyntaxhighlight>
 
{{output}}
Line 3,792 ⟶ 4,667:
=={{header|Ursa}}==
{{trans|Awk}}
<langsyntaxhighlight lang="ursa"># ursa appends to files by default when the out function is used
 
# create new passwd in working directory
Line 3,819 ⟶ 4,694:
while (f.hasline)
out (in string f) endl console
end while</langsyntaxhighlight>
 
=={{header|Visual Basic .NET}}==
{{trans|C#}}
<langsyntaxhighlight lang="vbnet">Imports System.IO
 
Module Module1
Line 3,876 ⟶ 4,751:
End Sub
 
End Module</langsyntaxhighlight>
{{out}}
<pre>Appended record: xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash</pre>
Line 3,884 ⟶ 4,759:
 
To append a record to an existing file in a CLI script, a little digging is required as the method to do this (''File.openWithFlags'') is currently undocumented. However, the following works fine.
<langsyntaxhighlight ecmascriptlang="wren">import "io" for File, FileFlags
 
var records = [
Line 3,912 ⟶ 4,787:
contents = File.read(fileName)
System.print("Records after appending new one:\n")
System.print(contents)</langsyntaxhighlight>
 
{{out}}
Line 3,944 ⟶ 4,819:
 
=={{header|Yabasic}}==
<langsyntaxhighlight Yabasiclang="yabasic">a = open("passwd", "a") // Open the file for appending, i.e. what you write to the file will be appended after its initial contents.
// If the file does not exist, it will be created.
Line 3,982 ⟶ 4,857:
wend
 
close #a</langsyntaxhighlight>
 
=={{header|zkl}}==
Line 3,999 ⟶ 4,874:
|}
{{trans|Ruby}}
<langsyntaxhighlight lang="zkl">var [const]
gnames=T("fullname","office","extension","homephone","email"),
pnames=T("account","password","uid","gid","gecos","directory","shell");
Line 4,012 ⟶ 4,887:
fcn init(str){ pnames.zipWith(setVar,vm.arglist) }
fcn toString { pnames.apply(setVar).concat(":") }
}</langsyntaxhighlight>
The class setVar method takes one or two parameters. With two, it sets the named class variable to a value; with one, it gets the var.
If there aren't enough parameters, the missing ones with be set to Void (yeah, poor error checking).
<langsyntaxhighlight lang="zkl">fcn strToPasswd(str){ // blow apart file line to class
p:=str.strip().split(":");
g:=Gecos(p[4].split(",").xplode());
Passwd(p[0,4].xplode(),g,p[5,*].xplode());
}</langsyntaxhighlight>
The List xplode method pushes the list contents to the parameter list.
<langsyntaxhighlight lang="zkl">jsmith:=Passwd("jsmith","x",1001, 1000,
Gecos("Joe Smith", "Room 1007", "(234)555-8917", "(234)555-0077", "jsmith@rosettacode.org"),
"/home/jsmith", "/bin/bash");
Line 4,036 ⟶ 4,911:
f.writeln(xyz); f.close();
 
File(filename).read().text.print(); // print file</langsyntaxhighlight>
{{out}}
<pre>
Line 4,043 ⟶ 4,918:
xyz:x:1003:1000:X Yz,Room 1003,(234)555-8913,(234)555-0033,xyz@rosettacode.org:/home/xyz:/bin/bash
</pre>
 
{{omit from|EasyLang}}
Anonymous user