-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Ralf Wildenhues on 10/15/2008 12:43 PM: >> e.g., regex classes, where 's/[^0-9]//' becomes 's/^0-9//' unless one >> doubles the square braces like so 's/[[^0-9]]//' in which case one of >> each pair is stripped away to get the desired form in the resulting >> 'configure' file. But that may not be the correct way to handle it. > > It's a valid way. You can move the quotes outward: > > $some_normal_code > [ $double_quoted_code > .. > sed 's/[^0-9]//' ... > $more_double_quoted_code > ] In fact, it is considered good style to move the quotes outward, as it makes it easier to copy and paste blocks of code. >> I guess the manual is trying to tell me that implicitly by discussing >> the m4 processor parsing rules, but I haven't yet found an explicit >> warning to that effect about use of shell commands (except the >> warnings about portable shell programming and recomended non-use of >> the negated character class form). http://www.gnu.org/software/autoconf/manual/autoconf.html#Active-Characters http://www.gnu.org/software/autoconf/manual/autoconf.html#Quotation-Rule-Of-Thumb give the best summary. Basically, use [foo] as a macro argument if you want foo to be reparsed as a macro name, and [[foo]] as a macro argument if you want it treated as literal text. In your case, you want the regex to be literal text, so [[ case $foo in [0-9]*) ;; esac ]] is the right quoting. If you have improvements for the wording in the manual, please let us know! - -- Don't work too hard, make some time for fun as well! Eric Blake ebb9@xxxxxxx -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkj2ltIACgkQ84KuGfSFAYDZxQCdFf7M9Lu3bNJ8la6TWGgYyqld 8XYAn1rr8zIaWNomsAtc7fSkKlkE1lrR =jxs0 -----END PGP SIGNATURE----- _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
