CODEWITHSUNDEEP
pythonlinuxperlsed
Pushpe
Pushpe

Reputation: 15

How to replace a string in multiple files?

I want to replace a string which occurs in several files. For a single file I am able to do using unix command :

sed 's/error("/printf( "ERROR : /g' all_reset_test.c > new_reset/all_reset_test.c

which replaces all 'error("' with 'printf( "ERROR : ' in this file.

But I have over 100 files for which I need to do this. I am looking for how to run this command for all files at once in either a perl or a python script.

Upvotes: 0

Views: 171

Answers (5)

branch14
branch14

Reputation: 1262

You can use sed's option -i

Quoting from sed's manpage:

-i[SUFFIX], --in-place[=SUFFIX]

      edit files in place (makes backup if extension supplied)

If you omit the SUFFIX sed will not create a backup before modifying the file.

In your case this

sed -i 's/error("/printf( "ERROR : /g' *.c

should do the job (without pyhton, perl, or a bash loop).

Upvotes: 1

Miguel Prz
Miguel Prz

Reputation: 13792

For example, if your files have the extension .txt, you can use this:

%> perl -pi -e 's/error("/printf( "ERROR : /' *.txt

Upvotes: 1

Brian Agnew
Brian Agnew

Reputation: 272307

You can iterate over files in the shell e.g. this finds all the .txt files in the subdirectories below the current directory. Each file is available in $f

for f in $(find . -name \*.txt); do
   # run my sed script for $f
done

There are numerous options for iterating over a set of files using bash. See here for some options. If you filenames have spaces, you will have to be careful, and this SO question/answer details some options.

Upvotes: 0

Roberto Reale
Roberto Reale

Reputation: 4317

Just wrap your sed command in a for cycle:

for file in $(cat file_list)
do
    sed 's/error("/printf( "ERROR : /g' $file > new_reset/$file
done

Of course, the list of files to edit can be obtained in multiple ways:

for file in $(ls *.c)  # if the files are in the same folder
do
    sed 's/error("/printf( "ERROR : /g' $file > new_reset/$file
done

Or

for file in $(find -type f -name '*.c')
do
    sed 's/error("/printf( "ERROR : /g' $file > new_reset/$file
done

Upvotes: 0

Hunter McMillen
Hunter McMillen

Reputation: 61510

You can use a simple bash for loop to apply this logic to all of your files: 

for f in $(ls *.c); do 
   sed 's/error("/printf( "ERROR : /g' ${f} > new_reset/${f}
done

The $(ls *.c) portion should be replaced by whatever ls command will select the files that you want to apply the sed command to.

Upvotes: 0

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