How to make filter on an output based on string lines?

Question

I have the following output

$ mycommand
1=aaa
1=eee
12=cccc
15=bbb

And I have a string str containing:

eee
cccc

and I want to display only lines which contains string exist in the string lines

So my out put will be:

$ mycommand | use_awk_or_sed_or_any_command
1=eee
12=cccc

How do you mean "string 'str' containing ...?" – kamae May 08 '14 at 13:42 — kamae, May 08 '14 at 13:42

score 2 · Answer 1 · answered May 07 '14 at 13:56

2

If you store the strings in a file, you can use grep with its -f option:

$ cat  search
eee
cccc

$ grep -wf search file
1=eee
12=cccc

You might also need the -F option if your strings contain special characters like ., $ etc.

answered May 07 '14 at 13:56

choroba

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it works if I m using files. But How I can make it work if my output is from command and the search string is a shell variable – MOHAMED May 07 '14 at 14:28

score 2 · Answer 2 · answered May 08 '14 at 13:24

Say your command is echo -e "1=aaa\n1=eee\n12=cccc\n15=bbb", you could do

echo -e "1=aaa\n1=eee\n12=cccc\n15=bbb" | grep -wE "$(sed  'N;s/\n/|/' <<<"$str")"

The sed command simply replaces the newline (\n) with | which is used by grep -E (for extended regular expressions) to separate multiple patterns. This means that the grep will print lines matching either eee or cccc. The w ensures that the match is of an entire word, so that things like eeeeee will not be matched.

How to make filter on an output based on string lines?

2 Answers2