uniq.1 (997B)
1 .TH UNIQ 1 sbase\-VERSION 2 .SH NAME 3 uniq \- multi-column 4 .SH SYNOPSIS 5 .B uniq 6 .RB [ \-cdu ] 7 .RI [ file ] 8 .SH DESCRIPTION 9 .B uniq 10 reads file and writes one copy of a line 11 from each group of consecutive duplicate lines 12 to stdout. 13 If no file is given, uniq reads from stdin. 14 .SH OPTIONS 15 .TP 16 .B \-c 17 prefixes each line with a count 18 of its consecutive occurrences in the input. 19 .TP 20 .B \-d 21 suppresses non-duplicate lines 22 (thus 'uniq -d' prints only duplicates). 23 .TP 24 .B \-u 25 suppresses non-unique lines 26 (thus 'uniq -u' prints only uniques). 27 .SH BUGS 28 The original sbase implementation of 29 .B uniq 30 supported multiple input-file arguments, 31 as e.g. cat and grep do. 32 Unfortunately, POSIX uniq treats its second argument (if present) 33 as an output filename and clobbers it. 34 Since users and scripts which rely on uniq 35 supporting multiple input-file arguments 36 would be at risk of data loss 37 if they ever ran into a POSIX-compatible uniq, 38 support for multiple input-file arguments 39 was removed from this implementation.