How to I find and replace every occurrence of:
subdomainA.example.com
with
subdomainB.example.com
in every text file under the /home/www/ directory tree (recursive find/replace).
views:
3148answers:
7
+10
A:
cd /home/www && find . -type f -print0 |
xargs -0 perl -i.bak -pe 's/subdomainA\.example\.com/subdomainB.example.com/g'
Employed Russian
2009-10-17 21:13:43
maybe put backslashes before the dots in the first half of the perl s/// substituion, but it's not likely to matter.
Ry4an
2009-10-17 21:15:17
+1 for the print0
roe
2009-10-17 21:18:06
I'm curious, is there a reason to use `-print0` and `xargs` instead of `-exec` or `-execdir`?
Philipp
2009-10-18 08:26:36
There is: from "man find": The specified command is run once for each matched file. That is, if there are 2000 files in /home/www, then 'find ... -exec ...' will result in 2000 invocations of perl; whereas 'find ... | xargs ...' will only invoke perl once or twice (assuming ARG_MAX of about 32K and average file name length of 20).
Employed Russian
2009-10-18 15:54:00
@Employed Russian: that's why you'd use `find -exec command {} +` - it does avoid excessive invocations of the command like xargs, but without the separate process.
John Zwinck
2009-10-18 19:27:07
On which platform? The xargs solution is portable, the "magic" invocations of "find ... -exec" which do not invoke a subprocess for every file found are not.
Employed Russian
2009-10-18 20:47:48
+6
A:
cd /home/www
find . -type f -print0 | xargs -0 sed -i 's/subdomainA.example.com/subdomainB.example.com/g'
UPD.
-print0 (GNU find only) tells find to use the null character (\0) instead of whitespace as the output delimiter between pathnames found. This is a safer option if you files can contain blanks or other special character. It is recommended to use the -print0 argument to find if you use -exec command or xargs (the -0 argument is needed in xargs.).
Fedyashev Nikita
2009-10-17 21:32:15
2Philipp: OK, this was new for me. Some explanation of this 2 parameters was added.
Fedyashev Nikita
2009-10-18 17:45:02
+1
A:
find /home/www/ -type f -exec perl -i.bak -pe 's/subdomainA\.example\.com/subdomainB.example.com/g' {} +
find /home/www/ -type f will list all files in /home/www/ (and its subdirectories). The "-exec" flag tells find to run the following command on each file found.
perl -i.bak -pe 's/subdomainA.example.com/subdomainB.example.com/g' {} +
is the command run on the files (many at a time). The "{}" gets replaced by file names. The + at the end of the command tells find to build 1 command for many filenames. From the find man page: "The command line is built in much the same way that xargs builds its command lines."
Thus it's possible to achieve your goal without using xargs -0, or -print0 . .
unutbu
2009-10-18 16:40:11
+1
A:
find /home/www/ -type f -exec \
sed -i 's/subdomainA\.example\.com/subdomainB.example.com/g' {} +
Compared to other answers here, this is simpler than most and uses sed instead of perl, which is what the original question asked for.
John Zwinck
2009-10-18 19:34:25
A:
muxh more simple way is to use the below on the command line
find /home/www/ -type f|xargs perl -pi -e 's/subdomainA\.example\.com/subdomainB.example.com/g'
Vijay Sarathi
2009-10-22 09:40:17
A:
You may also:
Search & replace with find & ed
http://codesnippets.joyent.com/posts/show/2299
(which also features a test mode via -t flag)
eddie
2010-06-28 12:16:41