Tru64 expr limitation

[Ralf Wildenhues]

Tru64 UNIX 5.1 expr is a bit borked, in that it converts the result of a
regex match into a number if possible.  :-(
  $ expr 00001 : '.*\(...\)'
  1
To see that converting is really done after matching:
  $ expr x00001 : '.*\(...\)'
  1
  $ expr x00001 : '\(...\)'
  x00

The effect in Autotest is that test directories are named
  ..
  testsuite.dir/9
  testsuite.dir/10
  ..

instead of the desired
  ..
  testsuite.dir/09
  testsuite.dir/10
  ..

I'd guess you prefer the unified behavior but a bit slower everywhere
instead, done in the patch below.  OK to apply?

Cheers,
Ralf

        * doc/autoconf.texi (Limitations of Usual Tools) <expr :>:
        Mention Tru64 expr bug that turns the result of a regex match
        into a number if possible.
        * lib/autotest/general.m4 (AT_INIT): Work around it using
        `echo | sed'.

Index: doc/autoconf.texi
===================================================================
RCS file: /cvsroot/autoconf/autoconf/doc/autoconf.texi,v
retrieving revision 1.954
diff -u -r1.954 autoconf.texi
--- doc/autoconf.texi   22 Feb 2006 19:18:23 -0000      1.954
+++ doc/autoconf.texi   4 Mar 2006 17:17:26 -0000
@@ -12203,6 +12609,14 @@
 simple workaround consists in testing @command{expr} and use a variable
 set to @command{expr} or to @command{false} according to the result.
 
+Tru64 @command{expr} will treat the result as a number, if it can be
+interpreted that way:
+
address@hidden
+$ @kbd{expr 00001 : '.*\(...\)'}
+1
address@hidden example
+
 
 @item @command{fgrep}
 @c ------------------
Index: lib/autotest/general.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autotest/general.m4,v
retrieving revision 1.196
diff -u -r1.196 general.m4
--- lib/autotest/general.m4     11 Jan 2006 08:33:16 -0000      1.196
+++ lib/autotest/general.m4     4 Mar 2006 17:17:26 -0000
@@ -666,7 +666,7 @@
       esac
 
       # Normalize the test group number.
-      at_group_normalized=`expr "00000$at_group" : ".*\($at_format\)"`
+      at_group_normalized=`echo "00000$at_group" | sed 
"s,.*\($at_format\),\1,"`
 
       # Create a fresh directory for the next test group, and enter.
       at_group_dir=$at_suite_dir/$at_group_normalized
@@ -935,7 +935,7 @@
       for at_group in $at_fail_list
       do
         # Normalize the test group number and cat the log.
-        at_group_normalized=`expr "00000$at_group" : ".*\($at_format\)"`
+       at_group_normalized=`echo "00000$at_group" | sed 
"s,.*\($at_format\),\1,"`
         cat "$at_suite_dir/$at_group_normalized/$as_me.log"
         echo
       done