[bug-gawk] gawk character class bug

[Ed Morton]

There's a bug in gawk wrt issuing a warning for character classes being used in 
a bracket expression. I want to remove the first character in a string that's 
either a closing  square bracket "]" or a space "[:space:]".In 
/usr/xpg4/bin/awk on Solaris I can do this: 

$ echo "a]b" | /usr/xpg4/bin/awk '{sub(/[][:space:]]/,"")}1' 
ab

In gawk it works just fine too and does correctly understand that [:space:]  is 
a character class BUT I get an unwarranted warning message: 

$ echo "a]b" | gawk '{sub(/[][:space:]]/,"")}1'             
gawk: cmd. line:1: warning: regexp component `[:space:]' should probably be 
`[[:space:]]' 
ab 

See the discussion at 
https://groups.google.com/forum/#!topic/comp.lang.awk/MGX4VKyuv0k  for more 
info.

Regards,

    Ed Morton.