Post date: Dec 21, 2009 8:54:06 AM
Q. I had written lots of code in C for my school work and saved it as source code under /home/user/c/*.c and *.h. How do I find files by content such as string or words (function name such as main() under UNIX shell prompt?
A. You need to use following tools:
[a] grep command : print lines matching a pattern.
[b] find command: search for files in a directory hierarchy.
grep command to find files by content
Type the command as follows:
grep 'string' *.txt
grep 'main(' *.c
grep '#include<example.h>' *.c
grep 'getChar*' *.c
grep -i 'ultra' *.conf
grep -iR 'ultra' *.conf
Where
-i : Ignore case distinctions in both the PATTERN (match valid, VALID, ValID string) and the input files (math file.c FILE.c FILE.C filename).
-R : Read all files under each directory, recursively
Highlighting searched patterns
You can highlight patterns easily while searching large number of files:
$ grep --color=auto -iR 'getChar();' *.c
Displaying file names and line number for searched patterns
You may also need to display filenames and numbers:
$ grep --color=auto -iRnH 'getChar();' *.c
Where,
-n : Prefix each line of output with the 1-based line number within its input file.
-H Print the file name for each match. This is the default when there is more than one file to search.
$grep --color=auto -nH 'DIR' *
You can also use find command:
$ find . -name "*.c" -print | xargs grep "main("