Changing all occurrences in a folder

There is no way to do it using only sed. You'll need to use at least the find utility together:

find . -type f -exec sed -i.bak "s/foo/bar/g" {} \;

This command will create a .bak file for each changed file.

Notes:

• The -i argument for sed command is a GNU extension, so, if you are running this command with the BSD's sed you will need to redirect the output to a new file then rename it.
• The find utility does not implement the -exec argument in old UNIX boxes, so, you will need to use a | xargs instead.

For portability, I don't rely on features of sed that are specific to linux or BSD. Instead I use the overwrite script from Kernighan and Pike's book on the Unix Programming Environment.

The command is then

find /the/folder -type f -exec overwrite '{}' sed 's/old/new/g' {} ';'

And the overwrite script (which I use all over the place) is

#!/bin/sh
# overwrite:  copy standard input to output after EOF
# (final version)

# set -x

case $# in
0|1)        echo 'Usage: overwrite file cmd [args]' 1>&2; exit 2
esac

file=$1; shift
new=/tmp/$$.new; old=/tmp/$$.old
trap 'rm -f $new; exit 1' 1 2 15    # clean up files

if "$@" >$new               # collect input
then
    cp $file $old   # save original file
    trap 'trap "" 1 2 15; cp $old $file     # ignore signals
          rm -f $new $old; exit 1' 1 2 15   # during restore
    cp $new $file
else
    echo "overwrite: $1 failed, $file unchanged" 1>&2
    exit 1
fi
rm -f $new $old

The idea is that it overwrites a file only if a command succeeds. Useful in find and also where you would not want to use

sed 's/old/new/g' file > file  # THIS CODE DOES NOT WORK

because the shell truncates the file before sed can read it.

Might I suggest (after backing up your files):

find /the/folder -type f -exec sed -ibak 's/old/new/g' {} ';'

Example: inline replace {AutoStart} with 1 for all of the ini files under the /app/config/ folder and its child folders:

sed -i 's/{AutoStart}/1/g' /app/config/**/*.ini

This worked for me (on mac terminal, on Linux you don't need '' -e):

sed -i '' -e 's/old text/new text/g' `grep 'old text' -rl *`

the command grep 'old text' -rl * lists all files in the working directory (and subdirectories) where "old text" exists. This then is passed in sed.

If you are worried about clobbering files that you accidentally haven't considered, you can run grep with the recursive option first to see which files will be potentially changed:

grep -r 'searchstring' *

It's then not hard to put together something that will run the replacement on each of these files:

for f in $(grep -r 'searchstring' *)
do
    sed -i -e 's/searchstring/replacement/g' "$f"
done

(Only valid with GNU sed - adjustments would be needed for POSIX compatibility as the -i inplace option is a GNU extension):

Might want to try my mass search/replace Perl script. Has some advantages over chained-utility solutions (like not having to deal with multiple levels of shell metacharacter interpretation).

#!/usr/bin/perl

use strict;

use Fcntl qw( :DEFAULT :flock :seek );
use File::Spec;
use IO::Handle;

die "Usage: $0 startdir search replace\n"
    unless scalar @ARGV == 3;
my $startdir = shift @ARGV || '.';
my $search = shift @ARGV or
    die "Search parameter cannot be empty.\n";
my $replace = shift @ARGV;
$search = qr/\Q$search\E/o;

my @stack;

sub process_file($) {
    my $file = shift;
    my $fh = new IO::Handle;
    sysopen $fh, $file, O_RDONLY or
        die "Cannot read $file: $!\n";
    my $found;
    while(my $line = <$fh>) {
        if($line =~ /$search/) {
            $found = 1;
            last;
        }
    }
    if($found) {
        print "  Processing in $file\n";
        seek $fh, 0, SEEK_SET;
        my @file = <$fh>;
        foreach my $line (@file) {
            $line =~ s/$search/$replace/g;
        }
        close $fh;
        sysopen $fh, $file, O_WRONLY | O_TRUNC or
            die "Cannot write $file: $!\n";
        print $fh @file;
    }
    close $fh;
}

sub process_dir($) {
    my $dir = shift;
    my $dh = new IO::Handle;
    print "Entering $dir\n";
    opendir $dh, $dir or
        die "Cannot open $dir: $!\n";
    while(defined(my $cont = readdir($dh))) {
        next
            if $cont eq '.' || $cont eq '..';
        # Skip .swap files
        next
            if $cont =~ /^\.swap\./o;
        my $fullpath = File::Spec->catfile($dir, $cont);
        if($cont =~ /$search/) {
            my $newcont = $cont;
            $newcont =~ s/$search/$replace/g;
            print "  Renaming $cont to $newcont\n";
            rename $fullpath, File::Spec->catfile($dir, $newcont);
            $cont = $newcont;
            $fullpath = File::Spec->catfile($dir, $cont);
        }
        if(-l $fullpath) {
            my $link = readlink($fullpath);
            if($link =~ /$search/) {
                my $newlink = $link;
                $newlink =~ s/$search/$replace/g;
                print "  Relinking $cont from $link to $newlink\n";
                unlink $fullpath;
                my $res = symlink($newlink, $fullpath);
                warn "Symlink of $newlink to $fullpath failed\n"
                    unless $res;
            }
        }
        next
            unless -r $fullpath && -w $fullpath;
        if(-d $fullpath) {
            push @stack, $fullpath;
        } elsif(-f $fullpath) {
            process_file($fullpath);
        }
    }
    closedir($dh);
}

if(-f $startdir) {
    process_file($startdir);
} elsif(-d $startdir) {
    @stack = ($startdir);
    while(scalar(@stack)) {
        process_dir(shift(@stack));
    }
} else {
    die "$startdir is not a file or directory\n";
}

for i in $(ls);do sed -i 's/old_text/new_text/g' $i;done