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 occuring 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.
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>
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(char *buf, char * buf_end, 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 start; start++; } return 0; }
int replace(char *from, char *to, 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() { char *from = "Goodbye, London!"; char *to = "Hello, New York!"; 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 c++>#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>
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>
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>
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>
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>
Perl
<lang bash>perl -pi -e "s/Goodbye London\!/Hello New York\!/g;" 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>
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 is not supported on Windows 8.3 operating systems).
<lang python>import fileinput
for line in fileinput.input(inplace=True):
print(line.replace('Goodbye London!', 'Hello New York!'), end=)
</lang>
Ruby
Like Perl:
ruby -pi -e "gsub('Goodbye London!', 'Hello New York!')" a.txt b.txt c.txt
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>