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Top Forums UNIX for Dummies Questions & Answers Uniq using only the first field Post 302158463 by Tytalus on Tuesday 15th of January 2008 11:26:50 AM
Old 01-15-2008
The neat nawk solution will not always provide the same solution independent of line ordering though...

something like:

Code:
awk '{if ( length($0) > length(a[$1]) ) {a[$1]=$0}} END {for (i in a){print a[i]}}' file

will ensure you get the longest line (if that is a requirement).
 

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UNIQ(1) 						      General Commands Manual							   UNIQ(1)

NAME
uniq - report repeated lines in a file SYNOPSIS
uniq [ -udc [ +n ] [ -n ] ] [ input [ output ] ] DESCRIPTION
Uniq reads the input file comparing adjacent lines. In the normal case, the second and succeeding copies of repeated lines are removed; the remainder is written on the output file. Note that repeated lines must be adjacent in order to be found; see sort(1). If the -u flag is used, just the lines that are not repeated in the original file are output. The -d option specifies that one copy of just the repeated lines is to be written. The normal mode output is the union of the -u and -d mode outputs. The -c option supersedes -u and -d and generates an output report in default style but with each line preceded by a count of the number of times it occurred. The n arguments specify skipping an initial portion of each line in the comparison: -n The first n fields together with any blanks before each are ignored. A field is defined as a string of non-space, non-tab charac- ters separated by tabs and spaces from its neighbors. +n The first n characters are ignored. Fields are skipped before characters. SEE ALSO
sort(1), comm(1) UNIQ(1)
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