Question

Title my be ambiguous. Here’s an example of what I’m asking.

#ls -l

prints me out something like this

-rw-r--r-- 1 root root   5110 2011-10-08 19:36 test.txt
-rw-r--r-- 1 root root   5111 2011-10-08 19:38 test.txt
-rw-r--r-- 1 root root   5121 2011-10-08 19:36 5110.txt
-rw-r--r-- 1 root root   5122 2011-10-08 19:38 5111.txt

Say I wanted to use grep to find all filenames containing '511' and print out the size/filename of the file.

How do I grep for filenames '511', still print the filesize, and not have the output contain the top two rows.

thank you very much SO, reading man pages hasn’t helped me on this one.

Answer 1

You can use awk for this:

pax:~$ echo '
-rw-r--r-- 1 root root   5110 2011-10-08 19:36 test.txt
-rw-r--r-- 1 root root   5111 2011-10-08 19:38 test.txt
-rw-r--r-- 1 root root   5121 2011-10-08 19:36 5110.txt
-rw-r--r-- 1 root root   5122 2011-10-08 19:38 5111.txt
' | awk '{if (substr($8,1,3)=="511"){print $5" "$8}}'

5121 5110.txt
5122 5111.txt

It simply checks field 8 (the filename) to see if it starts with “511” and, if so, prints out fields 5 and 8, the size and name.