Note that sorting uniq's input is often useful.

Suggested by Eric Blake.

diff --git a/ChangeLog b/ChangeLog
index 83b14108713950f6a7ac7afd488949523864afd2..8d5c1ab84cfa9f32cdd92fd724d21e29b0b5ceff 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-12-18  Jim Meyering  <meyering@redhat.com>
+
+       * src/uniq.c (usage): Note that sorting uniq's input is often useful.
+       Suggested by Eric Blake.
+
 2007-12-15  Jim Meyering  <meyering@redhat.com>
 
        Version 6.9.91.

diff --git a/NEWS b/NEWS
index 60be2de8f1847c444a4681545bc53c6668ecde06..5285d51e6d111eb92b82b075675761288abb77a8 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,9 @@
 GNU coreutils NEWS                                    -*- outline -*-
 
+* Noteworthy changes in release 6.? (????-??-??) [?]
+
+
+
 * Noteworthy changes in release 6.9.91 (2007-12-15) [beta]
 
 ** Bug fixes

diff --git a/src/uniq.c b/src/uniq.c
index 2864522490b263b24f52d9d26bc6e4a5072466e1..5fcbed9a42c0fe89112e2d7b45de902569117b78 100644 (file)
--- a/src/uniq.c
+++ b/src/uniq.c
@@ -167,6 +167,13 @@ Mandatory arguments to long options are mandatory for short options too.\n\
 \n\
 A field is a run of whitespace, then non-whitespace characters.\n\
 Fields are skipped before chars.\n\
+"), stdout);
+     fputs (_("\
+\n\
+Note: while uniq can be useful even with unsorted input, in most applications\n\
+the input is sorted in a manner consistent with field-selection options.\n\
+E.g., use `sort' if `uniq' uses no such option (or simply use `sort -u');\n\
+use `sort -k 3b' with uniq -f2.\n\
 "), stdout);
       emit_bug_reporting_address ();
     }