Searching file content using GREP

A nice and easy way to search files for specific content in the files using GREP.

grep -rnw '/path/to/somewhere/' -e 'pattern'
  • -r or -R is recursive,
  • -n is line number, and
  • -w stands for match the whole word.
  • -l (lower-case L) can be added to just give the file name of matching files.

Along with these, --exclude--include--exclude-dir flags could be used for efficient searching:

  • This will only search through those files which have .c or .h extensions:
    grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"
    
  • This will exclude searching all the files ending with .o extension:
    grep --exclude=*.o -rnw '/path/to/somewhere/' -e "pattern"
    
  • For directories it’s possible to exclude a particular directory(ies) through --exclude-dirparameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/:
    grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"
    

For more options check man grep.

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Multiple commands in Linux

For those that do not know how to string multiple commands together, here is a quick reference for you:

[user@server foobar]$ command1 ; command2

The command is executed in the order it was written, but command 2 is executed even if there was an error in command 1.

[user@server foobar]$ command1 && command2

The command command2 is executed only if command1 was successful, no errors.

 

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