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, Dec 19 '13 at 17:07

score 5 · Accepted Answer · answered Dec 19 '13 at 17:13

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 '13 at 17:13

dogbane

score 4 · Answer 2 · edited May 23 '17 at 12:32

4

See this, so that one would do

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

edited May 23 '17 at 12:32

Community

answered Dec 19 '13 at 17:04

kbshimmyo

2 Answers2