Assuming we have four input files:
$ head file* ==> file1 <== 0000 0000 ==> file2 <== abcd 0000 abcd ==> file3 <== 0000x ==> file4 <== abcd file4 doesn't contain the pattern at all, file3 contains the pattern, but it's not on a line on its own, file1 has multiple lines that contain just the pattern, and file2 has exactly one line with just the pattern.
To get all files that contain the pattern anywhere:
$ grep -l '0000' file* file1 file2 file3 To get all files that contain lines with nothing but the pattern:
$ grep -lx '0000' file* file1 file2 And if you wanted only files that contain exactly one line with nothing but the pattern, you could use -c to get a count first:
$ grep -xc '0000' file* file1:2 file2:1 file3:0 file4:0 and then use awk to print only the files with exactly one match:
$ grep -xc '0000' file* | awk -F: '$2==1 {print $1}' file2 With GNU awk, you could also do this directly:
$ awk 'BEGINFILE {c=0} /^0000$/ {++c} ENDFILE {if (c==1) print FILENAME}' file* file2