Globally replace text in several files
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to replace every occurring instance of a piece of text in a group of text files with another one. For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
Ada
<lang Ada>with Ada.Strings.Unbounded, Ada.Text_IO, Ada.Command_Line, Ada.Directories;
procedure Global_Replace is
subtype U_String is Ada.Strings.Unbounded.Unbounded_String;
function "+"(S: String) return U_String renames
Ada.Strings.Unbounded.To_Unbounded_String;
function "-"(U: U_String) return String renames
Ada.Strings.Unbounded.To_String;
procedure String_Replace(S: in out U_String; Pattern, Replacement: String) is
-- example: if S is "Mary had a XX lamb", then String_Replace(S, "X", "little");
-- will turn S into "Mary had a littlelittle lamb"
-- and String_Replace(S, "Y", "small"); will not change S
Index : Natural;
begin
loop
Index := Ada.Strings.Unbounded.Index(Source => S, Pattern => Pattern);
exit when Index = 0;
Ada.Strings.Unbounded.Replace_Slice
(Source => S, Low => Index, High => Index+Pattern'Length-1,
By => Replacement);
end loop;
end String_Replace;
procedure File_Replace(Filename: String; Pattern, Replacement: String) is
-- applies String_Rplace to each line in the file with the given Filename
-- propagates any exceptions, when, e.g., the file does not exist
I_File, O_File: Ada.Text_IO.File_Type;
Line: U_String;
Tmp_Name: String := Filename & ".tmp";
-- name of temporary file; if that file already exists, it will be overwritten
begin
Ada.Text_IO.Open(I_File, Ada.Text_IO.In_File, Filename);
Ada.Text_IO.Create(O_File, Ada.Text_IO.Out_File, Tmp_Name);
while not Ada.Text_IO.End_Of_File(I_File) loop
Line := +Ada.Text_IO.Get_Line(I_File);
String_Replace(Line, Pattern, Replacement);
Ada.Text_IO.Put_Line(O_File, -Line);
end loop;
Ada.Text_IO.Close(I_File);
Ada.Text_IO.Close(O_File);
Ada.Directories.Delete_File(Filename);
Ada.Directories.Rename(Old_Name => Tmp_Name, New_Name => Filename);
end File_Replace;
Pattern: String := Ada.Command_Line.Argument(1); Replacement: String := Ada.Command_Line.Argument(2);
begin
Ada.Text_IO.Put_Line("Replacing """ & Pattern
& """ by """ & Replacement & """ in"
& Integer'Image(Ada.Command_Line.Argument_Count - 2)
& " files.");
for I in 3 .. Ada.Command_Line.Argument_Count loop
File_Replace(Ada.Command_Line.Argument(I), Pattern, Replacement);
end loop;
end Global_Replace;</lang>
Ouput:
> ls ?.txt 1.txt 2.txt x.txt y.txt > more 2.txt This is a text. "Goodbye London!" "Goodbye London!" "Byebye London!" "Byebye London!" "Byebye London!" > ./global_replace "Goodbye London" "Hello New York" ?.txt Replacing "Goodbye London" by "Hello New York" in 4 files. > more 2.txt This is a text. "Hello New York!" "Hello New York!" "Byebye London!" "Byebye London!" "Byebye London!"
AutoHotkey
<lang AutoHotkey>SetWorkingDir %A_ScriptDir% ; Change the working directory to the script's location listFiles := "a.txt|b.txt|c.txt" ; Define a list of files in the current working directory loop, Parse, listFiles, | { ; The above parses the list based on the | character fileread, contents, %A_LoopField% ; Read the file fileDelete, %A_LoopField% ; Delete the file stringReplace, contents, contents, Goodbye London!, Hello New York!, All ; replace all occurrences fileAppend, %contents%, %A_LoopField% ; Re-create the file with new contents } </lang>
AWK
<lang AWK>
- syntax: GAWK -f GLOBALLY_REPLACE_TEXT_IN_SEVERAL_FILES.AWK filename(s)
BEGIN {
old_text = "Goodbye London!" new_text = "Hello New York!"
} BEGINFILE {
nfiles_in++ text_found = 0 delete arr
} { if (gsub(old_text,new_text,$0) > 0) {
text_found++ } arr[FNR] = $0
} ENDFILE {
if (text_found > 0) {
nfiles_out++
close(FILENAME)
for (i=1; i<=FNR; i++) {
printf("%s\n",arr[i]) >FILENAME
}
}
} END {
printf("files: %d read, %d updated\n",nfiles_in,nfiles_out)
exit(0)
} </lang>
<lang awk>@include "readfile" BEGIN {
while(++i < ARGC)
print gensub("Goodbye London!","Hello New York!","g", readfile(ARGV[i])) > ARGV[i]
}</lang>
BASIC
Pass the files on the command line (i.e. global-replace *.txt).
<lang qbasic>CONST matchtext = "Goodbye London!" CONST repltext = "Hello New York!" CONST matchlen = LEN(matchtext)
DIM L0 AS INTEGER, x AS INTEGER, filespec AS STRING, linein AS STRING
L0 = 1 WHILE LEN(COMMAND$(L0))
filespec = DIR$(COMMAND$(L0))
WHILE LEN(filespec)
OPEN filespec FOR BINARY AS 1
linein = SPACE$(LOF(1))
GET #1, 1, linein
DO
x = INSTR(linein, matchtext)
IF x THEN
linein = LEFT$(linein, x - 1) & repltext & MID$(linein, x + matchlen)
' If matchtext and repltext are of equal length (as in this example)
' then you can replace the above line with this:
' MID$(linein, x) = repltext
' This is somewhat more efficient than having to rebuild the string.
ELSE
EXIT DO
END IF
LOOP
' If matchtext and repltext are of equal length (as in this example), or repltext
' is longer than matchtext, you could just write back to the file while it's open
' in BINARY mode, like so:
' PUT #1, 1, linein
' But since there's no way to reduce the file size via BINARY and PUT, we do this:
CLOSE
OPEN filespec FOR OUTPUT AS 1
PRINT #1, linein;
CLOSE
filespec = DIR$
WEND
L0 += 1
WEND</lang>
BBC BASIC
<lang bbcbasic> FindThis$ = "Goodbye London!"
ReplaceWith$ = "Hello New York!"
DIM Files$(3)
Files$() = "C:\test1.txt", "C:\test2.txt", "C:\test3.txt", "C:\test4.txt"
FOR f% = 0 TO DIM(Files$(),1)
infile$ = Files$(f%)
infile% = OPENIN(infile$)
IF infile%=0 ERROR 100, "Failed to open file " + infile$
tmpfile$ = @tmp$+"replace.txt"
tmpfile% = OPENOUT(tmpfile$)
WHILE NOT EOF#infile%
INPUT #infile%, a$
IF ASCa$=10 a$ = MID$(a$,2)
l% = LEN(FindThis$)
REPEAT
here% = INSTR(a$, FindThis$)
IF here% a$ = LEFT$(a$,here%-1) + ReplaceWith$ + MID$(a$,here%+l%)
UNTIL here% = 0
PRINT #tmpfile%, a$ : BPUT #tmpfile%,10
ENDWHILE
CLOSE #infile%
CLOSE #tmpfile%
OSCLI "DEL """ + infile$ + """"
OSCLI "REN """ + tmpfile$ + """ """ + infile$ + """"
NEXT
END</lang>
C
<lang C>#include <stdio.h>
- include <stdlib.h>
- include <stddef.h>
- include <string.h>
- include <sys/types.h>
- include <fcntl.h>
- include <sys/stat.h>
- include <unistd.h>
- include <err.h>
- include <string.h>
char * find_match(const char *buf, const char * buf_end, const char *pat, size_t len) { ptrdiff_t i; char *start = buf; while (start + len < buf_end) { for (i = 0; i < len; i++) if (start[i] != pat[i]) break;
if (i == len) return (char *)start; start++; } return 0; }
int replace(const char *from, const char *to, const char *fname) {
- define bail(msg) { warn(msg" '%s'", fname); goto done; }
struct stat st; int ret = 0; char *buf = 0, *start, *end; size_t len = strlen(from), nlen = strlen(to); int fd = open(fname, O_RDWR);
if (fd == -1) bail("Can't open"); if (fstat(fd, &st) == -1) bail("Can't stat"); if (!(buf = malloc(st.st_size))) bail("Can't alloc"); if (read(fd, buf, st.st_size) != st.st_size) bail("Bad read");
start = buf; end = find_match(start, buf + st.st_size, from, len); if (!end) goto done; /* no match found, don't change file */
ftruncate(fd, 0); lseek(fd, 0, 0); do { write(fd, start, end - start); /* write content before match */ write(fd, to, nlen); /* write replacement of match */ start = end + len; /* skip to end of match */ /* find match again */ end = find_match(start, buf + st.st_size, from, len); } while (end);
/* write leftover after last match */ if (start < buf + st.st_size) write(fd, start, buf + st.st_size - start);
done: if (fd != -1) close(fd); if (buf) free(buf); return ret; }
int main() { const char *from = "Goodbye, London!"; const char *to = "Hello, New York!"; const char * files[] = { "test1.txt", "test2.txt", "test3.txt" }; int i;
for (i = 0; i < sizeof(files)/sizeof(char*); i++) replace(from, to, files[i]);
return 0; }</lang>
C++
<lang cpp>#include <fstream>
- include <iterator>
- include <boost/regex.hpp>
- include <string>
- include <iostream>
int main( int argc , char *argv[ ] ) {
boost::regex to_be_replaced( "Goodbye London\\s*!" ) ;
std::string replacement( "Hello New York!" ) ;
for ( int i = 1 ; i < argc ; i++ ) {
std::ifstream infile ( argv[ i ] ) ;
if ( infile ) {
std::string filetext( (std::istreambuf_iterator<char>( infile )) , std::istreambuf_iterator<char>( ) ) ; std::string changed ( boost::regex_replace( filetext , to_be_replaced , replacement )) ; infile.close( ) ; std::ofstream outfile( argv[ i ] , std::ios_base::out | std::ios_base::trunc ) ; if ( outfile.is_open( ) ) { outfile << changed ; outfile.close( ) ; }
}
else
std::cout << "Can't find file " << argv[ i ] << " !\n" ;
} return 0 ;
}</lang>
Modern C++ version: <lang cpp>#include <regex>
- include <fstream>
using namespace std; using ist = istreambuf_iterator<char>; using ost = ostreambuf_iterator<char>;
int main(){
auto from = "Goodbye London!", to = "Hello New York!";
for(auto filename : {"a.txt", "b.txt", "c.txt"}) {
ifstream infile {filename};
string content {ist {infile}, ist{}};
infile.close();
ofstream outfile {filename};
regex_replace(ost {outfile}, begin(content), end(content), regex {from}, to);
}
return 0;
} </lang>
C#
<lang csharp> using System.Collections.Generic; using System.IO;
class Program {
static void Main() {
var files = new List<string> {
"test1.txt",
"test2.txt"
};
foreach (string file in files) {
File.WriteAllText(file, File.ReadAllText(file).Replace("Goodbye London!", "Hello New York!"));
}
}
} </lang>
Clojure
<lang clojure>(defn hello-goodbye [& more]
(doseq [file more] (spit file (.replace (slurp file) "Goodbye London!" "Hello New York!"))))</lang>
Common Lisp
<lang Lisp> (defun hello-goodbye (files)
(labels ((replace-from-file (file)
(with-open-file (in file)
(loop for line = (read-line in nil)
while line do
(loop for index = (search "Goodbye London!" line)
while index do
(setf (subseq line index) "Hello New York!"))
collecting line)))
(write-lines-to-file (lines file)
(with-open-file (out file :direction :output :if-exists :overwrite)
(dolist (line lines)
(write-line line out))))
(replace-in-file (file)
(write-lines-to-file (replace-from-file file) file)))
(map nil #'replace-in-file files)))
</lang>
D
<lang d>import std.file, std.array;
void main() {
auto from = "Goodbye London!", to = "Hello, New York!";
foreach (fn; "a.txt b.txt c.txt".split()) {
write(fn, replace(cast(string)read(fn), from, to));
}
}</lang>
Erlang
<lang Erlang> -module( globally_replace_text ).
-export( [in_files/3, main/1] ).
in_files( Old, New, Files ) when is_list(Old) ->
in_files( binary:list_to_bin(Old), binary:list_to_bin(New), Files );
in_files( Old, New, Files ) -> [replace_in_file(Old, New, X, file:read_file(X)) || X <- Files].
main( [Old, New | Files] ) -> in_files( Old, New, Files ).
replace_in_file( Old, New, File, {ok, Binary} ) -> replace_in_file_return( File, file:write_file(File, binary:replace(Binary, Old, New, [global])) ); replace_in_file( _Old, _New, File, {error, Error} ) ->
io:fwrite( "Error: Could not read ~p: ~p~n", [File, Error] ),
error.
replace_in_file_return( _File, ok ) -> ok; replace_in_file_return( File, {error, Error} ) -> io:fwrite( "Error: Could not write ~p: ~p~n", [File, Error] ),
error.
</lang>
- Output:
macbook-pro:rosettacode bengt$ ls ?.txt 1.txt 2.txt macbook-pro:rosettacode bengt$ more ?.txt "Goodbye London!" "Goodbye London!" "Byebye London!" "Byebye London!" "Byebye London!" ...skipping... "Goodbye London!" "Byebye London!" "Byebye London!" "Byebye London!" "Goodbye London!" macbook-pro:rosettacode bengt$ escript globally_replace_text.erl "Goodbye London\!" "Hello New York\!" ?.txt macbook-pro:rosettacode bengt$ more ?.txt "Hello New York!" "Hello New York!" "Byebye London!" "Byebye London!" "Byebye London!" ...skipping... "Hello New York!" "Byebye London!" "Byebye London!" "Byebye London!" "Hello New York!"
F#
<lang fsharp>open System.IO
[<EntryPoint>] let main args =
let textFrom = "Goodbye London!"
let textTo = "Hello New York!"
for name in args do
let content = File.ReadAllText(name)
let newContent = content.Replace(textFrom, textTo)
if content <> newContent then
File.WriteAllText(name, newContent)
0</lang>
Go
<lang go>package main
import (
"bytes" "io/ioutil" "log" "os"
)
func main() {
gRepNFiles("Goodbye London!", "Hello New York!", []string{
"a.txt",
"b.txt",
"c.txt",
})
}
func gRepNFiles(olds, news string, files []string) {
oldb := []byte(olds)
newb := []byte(news)
for _, fn := range files {
if err := gRepFile(oldb, newb, fn); err != nil {
log.Println(err)
}
}
}
func gRepFile(oldb, newb []byte, fn string) (err error) {
var f *os.File
if f, err = os.OpenFile(fn, os.O_RDWR, 0); err != nil {
return
}
defer func() {
if cErr := f.Close(); err == nil {
err = cErr
}
}()
var b []byte
if b, err = ioutil.ReadAll(f); err != nil {
return
}
if bytes.Index(b, oldb) < 0 {
return
}
r := bytes.Replace(b, oldb, newb, -1)
if err = f.Truncate(0); err != nil {
return
}
_, err = f.WriteAt(r, 0)
return
}</lang>
Haskell
The module Data.List provides some useful functions: tails (constructs substrings dropping elements from the head of the list), isPrefixOf (checks if a string matches the beginning of another one) and elemIndices (gets the list indices of all elements matching a value). This code doesn't rewrite the files, it just returns the changes made to the contents of the files. <lang Haskell>import Data.List (tails, elemIndices, isPrefixOf)
replace :: String -> String -> String -> String replace [] _ xs = xs replace _ [] xs = xs replace _ _ [] = [] replace a b xs = replAll
where
-- make substrings, dropping one element each time
xtails = tails xs
-- what substrings begin with the string to replace?
-- get their indices
matches = elemIndices True $ map (isPrefixOf a) xtails
-- replace one occurrence
repl ys n = take n ys ++ b ++ drop (n + length b) ys
-- replace all occurrences consecutively
replAll = foldl repl xs matches
replaceInFiles a1 a2 files = do
f <- mapM readFile files return $ map (replace a1 a2) f
</lang> This other version is more effective because it processes the string more lazily, replacing the text as it consumes the input string (the previous version was stricter because of "matches" traversing the whole list; that would force the whole string into memory, which could cause the system to run out of memory with large text files). <lang Haskell>replace _ _ [] = [] replace a b xx@(x:xs) =
if isPrefixOf a xx then b ++ replace a b (drop (length a) xx) else x : replace a b xs
</lang> Example:
File "t1.txt" contains: "Goodbye London! This is text 1." File "t2.txt" contains: "This is text 2. Goodbye London! Now we repeat: Goodbye London! And that's all." replaceInFiles "Goodbye London!" "Hello New York!" ["t1.txt", "t2.txt"]
Output:
["Hello New York! This is text 1.\n","This is text 2. Hello New York! Now we repeat: Hello New York! And that's all.\n"]
Icon and Unicon
This example uses the Unicon stat function. It can be rewritten for Icon to aggregate the file in a reads loop. <lang Icon>procedure main() globalrepl("Goodbye London","Hello New York","a.txt","b.txt") # variable args for files end
procedure globalrepl(old,new,files[])
every fn := !files do
if s := reads(f := open(fn,"bu"),stat(f).size) then {
writes(seek(f,1),replace(s,old,new))
close(f)
}
else write(&errout,"Unable to open ",fn)
end
link strings # for replace</lang>
J
If files is a variable with the desired list of file names:
<lang j>require'strings' (1!:2~rplc&('Goodbye London!';'Hello New York!')@(1!:1))"0 files</lang>
Java
Minimalistic version, assumes default encoding.
<lang java>import java.io.*; import java.nio.file.*;
public class GloballyReplaceText {
public static void main(String[] args) throws IOException {
for (String fn : new String[]{"test1.txt", "test2.txt"}) {
String s = new String(Files.readAllBytes(Paths.get(fn)));
s = s.replace("Goodbye London!", "Hello New York!");
try (FileWriter fw = new FileWriter(fn)) {
fw.write(s);
}
}
}
}</lang>
Julia
We will use Julia's built-in Perl-compatible regular-expressions. Although we could read in the files line by line, it is simpler and probably faster to just read the whole file into memory (as text files are likely to fit into memory on modern computers). <lang julia>filenames = ["f1.txt", "f2.txt"] for filename in filenames
txt = readall(filename)
open(filename, "w") do f
write(f, replace(txt, "Goodbye London!", "Hello New York!"))
end
end</lang>
Lasso
<lang Lasso>#!/usr/bin/lasso9
local(files = array('f1.txt', 'f2.txt'))
with filename in #files let file = file(#filename) let content = #file -> readbytes do { #file -> dowithclose => { #content -> replace('Goodbye London!', 'Hello New York!') #file -> opentruncate #file -> writebytes(#content) } }</lang>
Liberty BASIC
<lang lb> nomainwin
file$( 1) ="data1.txt" file$( 2) ="data2.txt" file$( 3) ="data3.txt"
for i =1 to 3
open file$( i) for input as #i
orig$ =input$( #i, lof( #i))
close #i
dummy$ =FindReplace$( orig$, "Goodbye London!", "Hello New York!", 1)
open "RC" +file$( i) for output as #o
#o dummy$;
close #o
next i
end
function FindReplace$( FindReplace$, find$, replace$, replaceAll) ' Target string, string to find, string to replace it with, flag 0/1 for 'replace all occurrences'.
if ( ( FindReplace$ <>"") and ( find$ <>"") ) then
fLen =len( find$)
rLen =len( replace$)
do
fPos =instr( FindReplace$, find$, fPos)
if not( fPos) then exit function
pre$ =left$( FindReplace$, fPos -1)
post$ =mid$( FindReplace$, fPos +fLen)
FindReplace$ =pre$ +replace$ +post$
fPos =fPos +( rLen -fLen) +1
loop while (replaceAll)
end if
end function </lang>
Lua
<lang lua>filenames = { "f1.txt", "f2.txt" }
for _, fn in pairs( filenames ) do
fp = io.open( fn, "r" ) str = fp:read( "*all" ) str = string.gsub( str, "Goodbye London!", "Hello New York!" ) fp:close()
fp = io.open( fn, "w+" ) fp:write( str ) fp:close()
end</lang>
Mathematica / Wolfram Language
<lang Mathematica>listOfFiles = {"a.txt", "b.txt", "c.txt"}; Do[
filename = listOfFilesi; filetext = Import[filename, "Text"]; filetext = StringReplace[filetext, "Goodbye London!" -> "Hello New York!"]; Export[filename, filetext, "Text"] , {i, 1, Length[listOfFiles]}]</lang>
File b.txt before the code is run:
second file for the Globally replace text in several files problem. Goodbye London! Goodbye London! Bye bye London! Bye bye London! Bye bye London!
File b.txt after the code is run:
second file for the Globally replace text in several files problem. Hello New York! Hello New York! Bye bye London! Bye bye London! Bye bye London!
Nim
<lang nim>import strutils
var fr = "Goodbye London!" var to = "Hello, New York!"
for fn in ["a.txt", "b.txt", "c.txt"]:
fn.writeFile fn.readFile.replace(fr, to)</lang>
OpenEdge/Progress
<lang progress>FUNCTION replaceText RETURNS LOGICAL (
i_cfile_list AS CHAR, i_cfrom AS CHAR, i_cto AS CHAR
):
DEF VAR ii AS INT. DEF VAR lcfile AS LONGCHAR.
DO ii = 1 TO NUM-ENTRIES( i_cfile_list ):
COPY-LOB FROM FILE ENTRY( ii, i_cfile_list ) TO lcfile.
lcfile = REPLACE( lcfile, i_cfrom, i_cto ).
COPY-LOB FROM lcfile TO FILE ENTRY( ii, i_cfile_list ).
END.
END FUNCTION. /* replaceText */
replaceText(
"a.txt,b.txt,c.txt", "Goodbye London!", "Hello New York!"
).</lang>
Pascal
<lang pascal>Program StringReplace;
uses
Classes, StrUtils;
const
fileName: array[1..3] of string = ('a.txt', 'b.txt', 'c.txt');
matchText = 'Goodbye London!';
replaceText = 'Hello New York!';
var
AllText: TStringlist; i, j: integer;
begin
for j := low(fileName) to high(fileName) do
begin
AllText := TStringlist.Create;
AllText.LoadFromFile(fileName[j]);
for i := 0 to AllText.Count-1 do
AllText.Strings[i] := AnsiReplaceStr(AllText.Strings[i], matchText, replaceText);
AllText.SaveToFile(fileName[j]);
AllText.Destroy;
end;
end.</lang>
Perl
<lang bash>perl -pi -e "s/Goodbye London\!/Hello New York\!/g;" a.txt b.txt c.txt</lang>
Perl 6
Current Perl 6 implementations do not yet support the -i flag for editing files in place, so we roll our own (rather unsafe) version:
<lang perl6>slurp($_).subst('Goodbye London!', 'Hello New York!', :g) ==> spurt($_)
for <a.txt b.txt c.txt>;</lang>
PicoLisp
<lang PicoLisp>(for File '(a.txt b.txt c.txt)
(call 'mv File (tmp File))
(out File
(in (tmp File)
(while (echo "Goodbye London!")
(prin "Hello New York!") ) ) ) )</lang>
PowerBASIC
<lang powerbasic>$matchtext = "Goodbye London!" $repltext = "Hello New York!"
FUNCTION PBMAIN () AS LONG
DIM L0 AS INTEGER, filespec AS STRING, linein AS STRING
L0 = 1
WHILE LEN(COMMAND$(L0))
filespec = DIR$(COMMAND$(L0))
WHILE LEN(filespec)
OPEN filespec FOR BINARY AS 1
linein = SPACE$(LOF(1))
GET #1, 1, linein
' No need to jump through FB's hoops here...
REPLACE $matchtext WITH $repltext IN linein
PUT #1, 1, linein
SETEOF #1
CLOSE
filespec = DIR$
WEND
INCR L0
WEND
END FUNCTION</lang>
PowerShell
<lang PowerShell> $listfiles = @('file1.txt','file2.txt') $old = 'Goodbye London!' $new = 'Hello New York!' foreach($file in $listfiles) {
(Get-Content $file).Replace($old,$new) | Set-Content $file
} </lang>
PureBasic
<lang PureBasic>Procedure GRTISF(List File$(), Find$, Replace$)
Protected Line$, Out$, OutFile$, i
ForEach File$()
fsize=FileSize(File$())
If fsize<=0: Continue: EndIf
If ReadFile(0, File$())
i=0
;
; generate a temporary file in a safe way
Repeat
file$=GetTemporaryDirectory()+base$+"_"+Str(i)+".tmp"
i+1
Until FileSize(file$)=-1
i=CreateFile(FileID, file$)
If i
; Copy the infile to the outfile while replacing any needed text
While Not Eof(0)
Line$=ReadString(0)
Out$=ReplaceString(Line$,Find$,Replace$)
WriteString(1,Out$)
Wend
CloseFile(1)
EndIf
CloseFile(0)
If i
; If we made a new file, copy it back.
CopyFile(file$, File$())
DeleteFile(file$)
EndIf
EndIf
Next
EndProcedure</lang> Implementation
NewList Xyz$() AddElement(Xyz$()): Xyz$()="C:\\a.txt" AddElement(Xyz$()): Xyz$()="C:\\b.txt" AddElement(Xyz$()): Xyz$()="D:\\c.txt" GRTISF(Xyz$(), "Goodbye London", "Hello New York")
Python
From Python docs. (Note: in-place editing does not work for MS-DOS 8+3 filesystems.).
<lang python>import fileinput
for line in fileinput.input(inplace=True):
print(line.replace('Goodbye London!', 'Hello New York!'), end=)
</lang>
Racket
Code wrapped in a convenient script: <lang racket>
- !/usr/bin/env racket
- lang racket
(define from-string #f) (define to-string #f)
(command-line
#:once-each
[("-f") from "Text to remove" (set! from-string from)]
[("-t") to "Text to put instead" (set! to-string to)]
#:args files
(unless from-string (error "No `from' string specified"))
(unless to-string (error "No `to' string specified"))
(when (null? files) (error "No files given"))
(define from-rx (regexp (regexp-quote from-string)))
(for ([file files])
(printf "Editing ~a..." file) (flush-output)
(define text1 (file->string file))
(define text2 (regexp-replace* from-rx text1 to-string))
(if (equal? text1 text2)
(printf " no change\n")
(begin (display-to-file text2 file #:exists 'replace)
(printf " modified copy saved in place\n")))))
</lang> Sample run:
$ ./replace -h replace [ <option> ... ] [<files>] ... where <option> is one of -f <from> : Text to remove -t <to> : Text to put instead --help, -h : Show this help -- : Do not treat any remaining argument as a switch (at this level) Multiple single-letter switches can be combined after one `-'; for example: `-h-' is the same as `-h --' $ ./replace -f "Goodbye London!" "Hello New York!" file* Editing file1... no change Editing file2... modified copy saved in place Editing file3... modified copy saved in place
REXX
version 1
This example works under "DOS" and/or "DOS" under Microsoft Windows.
Filenames that contain blanks should have their blanks replaced with commas.
<lang rexx>/*REXX program to read the files specified and globally replace a string*/
old = 'Goodbye London!' /*old text to be replaced. */
new = 'Hello New York!' /*new text used for replacement. */
parse arg fileList; files=words(fileList); pad=left(,20)
hdr='────── file' /*eyecatcher.*/
do f=1 for files; aFile=translate(word(fileList,f),,','); say; say
say hdr' is being read: ' aFile pad "("f 'out of' files "files)."
call linein aFile,1,0 /*position the file for input. */
changes=0 /*# changes in the file (so far).*/
do j=1 while lines(aFile)\==0 /*read a file (if it exists). */
@.j = linein(aFile) /*read a record from the file. */
if pos(old,@.j)==0 then iterate /*Anything to change? No, skip.*/
changes = changes+1 /*bump the change counter. */
@.j = changestr(old,@.j,new) /*change this record, old ──► new*/
end /*j*/
say hdr ' was read: ' aFile", with " j-1 'records.'
if changes == 0 then do
say hdr ' not changed: ' aFile
iterate /*f*/
end
call lineout aFile,,1 /*position the file for output. */
say hdr 'being changed: ' aFile
do r=1 for j-1; call lineout aFile,@.r; end /*re-write file.*/
say hdr 'was changed: ' aFile " with" changes 'lines changed.'
end /*f*/
/*stick a fork in it, we're done.*/</lang>
Some older REXXes don't have a changestr bif, so one is included here ──► CHANGESTR.REX.
output when using the input of: one.txt two.txt
────── file is being read: one.txt (1 out of 2 files). ────── file was read: one.txt, with 13 records. ────── file being changed: one.txt ────── file was changed: one.txt with 2 lines changed. ────── file is being read: two.txt (2 out of 2 files). ────── file was read: two.txt, with 59 records. ────── file being changed: two.txt ────── file was changed: two.txt with 6 lines changed.
Version 2
considering file ids that contain blanks
<lang rexx>/* REXX ***************************************************************
- Copy all files *.txt to *.rpl
- replacing all occurrences of old by new
- Execute in the directory containing the files to ne processed
- 16.01.2013 Walter Pachl
- ...if file names contain blanks
- /
Parse Arg a If a='?' Then Do
Do i=2 To 5 Say substr(sourceline(i),3) End Exit End
'dir *.rpl' Say 'May I erase *.rpl?' Parse Upper Pull answer If answer='Y' | answer='J' Then
'erase *.rpl'
Else Do
Say 'Giving up..' Exit End
old='Goodbye London!' new='Hello New York!' dir='dir.dir' 'dir *.* >' dir Do While lines(dir)>0
Parse Value linein(dir) With 37 f
Select
When f= |,
left(f,1)='.' |,
pos(' Bytes',f)>0 Then Iterate
When right(f,4)='.txt' Then
Call replace
Otherwise
Say left(f,50) 'not eligible for replacing'
End
End
Exit
replace: /* REXX ***************************************************************
- Copy a file fn.txt to fn.rpl
- replacing all occurrences of old by new
- /
oid=fn(f)'.rpl' cnt.=0 Do ii=1 By 1 While lines(f)>0
l=linein(f) ol=repl(l,new,old) Call lineout oid,ol End
Call lineout f Call lineout oid Select
When cnt.0changes=0 Then Do 'erase' oid Say left(f,50) 'no changes' End When cnt.0changes=1 Then Say left(f,50) '1 change' Otherwise Say left(f '->' oid,50) cnt.0changes 'changes' End
Return
fn: Procedure /* REXX ***************************************************************
- Get the file name of a file id
- /
parse Arg fid Parse Var fid fn '.' ft Return fn
repl: Procedure Expose cnt. /* REXX ***************************************************************
- Replace an old string by a new one
- /
Parse Arg s,new,old
ol=
Do Until p=0
p=pos(old,s)
If p>0 Then Do
ol=ol||left(s,p-1)||new
s=substr(s,p+length(old))
cnt.0changes=cnt.0changes+1
End
Else
ol=ol||s
End
Return ol</lang>
Sample output:
Datenträger in Laufwerk Z: ist H
Volumeseriennummer: FE17-3A89
Verzeichnis von Z:\glr
16.01.2013 09:55 283 input.rpl
16.01.2013 09:55 352 input2.rpl
16.01.2013 09:55 283 input file.rpl
3 Datei(en), 918 Bytes
0 Verzeichnis(se), 3.993.468.928 Bytes frei
May I erase *.rpl?
----> here I entered y
input.txt -> input.rpl 1 change
input.nix not eligible for replacing
input2.txt -> input2.rpl 4 changes
dir.dir not eligible for replacing
input file.txt -> input file.rpl 1 change
input3.txt no changes
Ruby
Like Perl:
ruby -pi -e "gsub('Goodbye London!', 'Hello New York!')" a.txt b.txt c.txt
Run BASIC
<lang runbasic>file$(1) ="data1.txt" file$(2) ="data2.txt" file$(3) ="data3.txt"
for i = 1 to 3
open file$(i) for input as #in
fileBefore$ = input$( #in, lof( #in))
close #in
fileAfter$ = strRep$(fileBefore$, "Goodbye London!", "Hello New York!")
open "new_" + file$(i) for output as #out
print #out,fileAfter$;
close #out
next i end
' -------------------------------- ' string replace - rep str with ' -------------------------------- FUNCTION strRep$(str$,rep$,with$) ln = len(rep$) ln1 = ln - 1 i = 1 while i <= len(str$)
if mid$(str$,i,ln) = rep$ then
strRep$ = strRep$ + with$
i = i + ln1
else
strRep$ = strRep$ + mid$(str$,i,1)
end if
i = i + 1 WEND END FUNCTION</lang>
Sed
<lang bash>sed -i 's/Goodbye London!/Hello New York!/g' a.txt b.txt c.txt</lang>
Seed7
<lang seed7>$ include "seed7_05.s7i";
include "getf.s7i";
const proc: main is func
local
var string: fileName is "";
var string: content is "";
begin
for fileName range [] ("a.txt", "b.txt", "c.txt") do
content := getf(fileName);
content := replace(content, "Goodbye London!", "Hello New York!");
putf(fileName, content);
end for;
end func;</lang>
Sidef
<lang ruby>var files = %w(
a.txt
b.txt
c.txt
);
files.map{.to_file}.each { |file|
say file.edit { |line|
line.gsub("Goodbye London!", "Hello New York!");
};
}</lang>
Tcl
<lang tcl>package require Tcl 8.5 package require fileutil
- Parameters to the replacement
set from "Goodbye London!" set to "Hello New York!"
- Which files to replace
set fileList [list a.txt b.txt c.txt]
- Make a command fragment that performs the replacement on a supplied string
set replacementCmd [list string map [list $from $to]]
- Apply the replacement to the contents of each file
foreach filename $fileList {
fileutil::updateInPlace $filename $replacementCmd
}</lang>
TUSCRIPT
<lang tuscript> $$ MODE TUSCRIPT files="a.txt'b.txt'c.txt"
BUILD S_TABLE search = ":Goodbye London!:"
LOOP file=files
ERROR/STOP OPEN (file,WRITE,-std-)
ERROR/STOP CREATE ("scratch",FDF-o,-std-)
ACCESS q: READ/STREAM/RECORDS/UTF8 $file s,aken+text/search+eken
ACCESS s: WRITE/ERASE/STREAM/UTF8 "scratch" s,aken+text+eken
LOOP
READ/EXIT q
IF (text.ct.search) SET text="Hello New York!"
WRITE/ADJUST s
ENDLOOP
ENDACCESS/PRINT q
ENDACCESS/PRINT s
ERROR/STOP COPY ("scratch",file)
ERROR/STOP CLOSE (file)
ENDLOOP ERROR/STOP DELETE ("scratch") </lang>
TXR
Extraction Language
<lang txr>@(next :args) @(repeat) @file @(next `@file`) @(freeform) @(coll :gap 0)@notmatch@{match /Goodbye, London!/}@(end)@*tail@/\n/ @(output `@file.tmp`) @(rep)@{notmatch}Hello, New York!@(end)@tail @(end) @(do @(rename-path `@file.tmp` file)) @(end)</lang> Run:
$ cat foo.txt aaaGoodbye, London!aaa Goodbye, London! $ cat bar.txt aaaGoodbye, London!aaa Goodbye, London! $ txr replace-files.txr foo.txt bar.txt $ cat foo.txt aaaHello, New York!aaa Hello, New York! $ cat bar.txt aaaHello, New York!aaa Hello, New York!
Run, with no directory permissions:
$ chmod a-w . $ txr replace-files.txr foo.txt bar.txt txr: unhandled exception of type file_error: txr: could not open foo.txt.tmp (error 13/Permission denied)
TXR Lisp
<lang txrlisp>(each ((fname *args*))
(let* ((infile (open-file fname))
(outfile (open-file `@fname.tmp` "w"))
(content (get-string infile))
(edited (regsub #/Goodbye, London/ "Hello, New York" content)))
(put-string edited outfile)
(rename-path `@fname.tmp` fname)))</lang>
UNIX Shell
<lang bash>replace() {
local search=$1 replace=$2
local file lines line
shift 2
for file in "$@"; do
lines=()
while IFS= read -r line; do
lines+=( "${line//$search/$replace}" )
done < "$file"
printf "%s\n" "${lines[@]}" > "$file"
done
} replace "Goodbye London!" "Hello New York!" a.txt b.txt c.txt</lang>
<lang bash>function replace {
typeset search=$1 replace=$2
typeset file lines line
shift 2
for file in "$@"; do
lines=()
while IFS= read -r line; do
lines+=( "${line//$search/$replace}" )
done < "$file"
printf "%s\n" "${lines[@]}" > "$file"
done
} replace "Goodbye London!" "Hello New York!" a.txt b.txt c.txt</lang>
VBScript
<lang VBScript> Const ForReading = 1 Const ForWriting = 2
strFiles = Array("test1.txt", "test2.txt", "test3.txt")
With CreateObject("Scripting.FileSystemObject") For i = 0 To UBound(strFiles) strText = .OpenTextFile(strFiles(i), ForReading).ReadAll() With .OpenTextFile(strFiles(i), ForWriting) .Write Replace(strText, "Goodbye London!", "Hello New York!") .Close End With Next End With </lang>
Vedit macro language
The list of files is in file "files.lst" which is expected to be in current directory. <lang vedit>File_Open("files.lst") // list of files to process
- 20 = Reg_Free // text register for filename
While(!At_EOF) {
Reg_Copy_Block(#20, Cur_Pos, EOL_Pos)
File_Open(@(#20))
Replace("Goodbye London!", "Hello New York!", BEGIN+ALL+NOERR)
Buf_Close(NOMSG)
Line(1, ERRBREAK)
}
Reg_Empty(#20) // Cleanup Buf_Quit(OK)</lang>
XPL0
<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations string 0; \use zero-terminated strings
func StrLen(A); \Return number of characters in an ASCIIZ string char A; int I; for I:= 0 to -1>>1-1 do
if A(I) = 0 then return I;
func StrFind(A, B); \Search for ASCIIZ string A in string B \Returns address of first occurrence of string A in B, or zero if A is not found char A, B; \strings to be compared int LA, LB, I, J; [LA:= StrLen(A); LB:= StrLen(B); for I:= 0 to LB-LA do
[for J:= 0 to LA-1 do
if A(J) # B(J+I) then J:= LA+1;
if J = LA then return B+I; \found
];
return 0; ];
proc ReplaceText(FileName); \replace text in specified file char FileName; char Str(1_000_000), Hello, Bye, Pointer; int Handle, I, C; [Handle:= FOpen(FileName, 0); \get handle for input file FSet(Handle, ^I); \set device 3 input to file handle OpenI(3); \initialize buffer pointers I:= 0; repeat C:= ChIn(3); \read file into memory
Str(I):= C;
I:= I+1;
until C = $1A; \EOF FClose(Handle); \release handle
Hello:= "Hello New York!"; \replacement text Bye:= "Goodbye London!"; Pointer:= StrFind(Bye, Str); if Pointer \#0\ then \overwrite (both strings are same length)
for I:= 0 to 15-1 do Pointer(I):= Hello(I);
Handle:= FOpen(FileName, 1); \get handle for output file FSet(Handle, ^O); \set device 3 output to file handle OpenO(3); I:= 0; repeat C:= Str(I); \write file from memory
I:= I+1;
ChOut(3, C);
until C = $1A; \EOF Close(3); \flush output buffer FClose(Handle); \release handle ];
int File, I; [File:= ["Alpha.txt", "Beta.txt", "Gamma.txt", "Delta.txt"]; for I:= 0 to 4-1 do ReplaceText(File(I)); ]</lang>
zkl
<lang zkl>fcn sed(data,src,dst){
srcSz:=src.len(); dstSz:=dst.len(); md5:=Utils.MD5.calc(data);
n:=0; while(Void!=(n:=data.find(src,n)))
{ data.del(n,srcSz); data.insert(n,dst); n+= dstSz; }
return(md5!=Utils.MD5.calc(data)); // changed?
} fcn sedFile(fname,src,dst){
f:=File(fname,"r"); data:=f.read(); f.close();
if(sed(data,"Goodbye London!", "Hello New York!"))
{ f:=File(fname,"w"); f.write(data); f.close(); }
}</lang> This is a read file/blast it/write if changed. You could also do it line by line. <lang zkl>vm.arglist.apply2(sedFile); $ zkl bbb foo.txt bar.txt</lang> The apply2 method doesn't return anything, it is a side effects method. You could also easily thread this (by using sedFile.launch or sedFile.strand depending on if you wanted a true thread or a co-op thread). I didn't because I didn't want to bother with checking for duplicate files or file locking. vm.arglist, when passed to "main" (the constructor of the file being run) is a copy of argv that has been pruned.
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