Print a dash if grep not found

Question

I would like this command to print a dash if grep not found (in addition to the new line already coded):

while read vl ; do grep -w "$vl" APL_vs_HS.tab || printf "\n" ; done < 1

Thanks! Bernardo

By "grep not found", do you mean that the grep command doesn't exist, or that grep doesn't find the pattern? I presume the latter, but the way you phrased it implies the former. — Keith Thompson
– Keith Thompson, Commented Dec 19, 2013 at 17:07

dogbane · Accepted Answer · 2013-12-19 17:13:38Z

5

Why do you need to use printf? Simply use echo, then you won't need to worry about printing a newline because echo automatically outputs one.

while read vl ; do grep -w "$vl" APL_vs_HS.tab || echo "-" ; done < 1

answered Dec 19, 2013 at 17:13

dogbane

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Community · Accepted Answer · 2017-05-23 12:32:18Z

4

See this, so that one would do

while read vl; do grep -w "$vl" APL_vs_HS.tab || printf -- "-\n" ; done < 1

CommunityBot

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answered Dec 19, 2013 at 17:04

kbshimmyo

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