From UNIX shell, how to find all files containing a specific string, then print the 4th line of each file? -


i want find files within current directory contain given string, print 4th line of each file. 

grep --null -l "$yourstring" * | # list files containing string   xargs -0 sed -n '4p;q' # print fourth line of said files.

different editions of grep have different incantations of --null, it's there in form. read manpage details.

update: believe 1 of null file list incantations of grep reasonable solution cover vast majority of real-world use cases, entirely portable, if version of grep not support null output not safe use xargs, must resort find.

find . -maxdepth 1 -type f -exec grep -q "$yourstring" {} \; -exec sed -n '4p;q' {} +

because find arguments can used predicates, -exec grep -q… part filters files fed sed down contain required string.


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