Document limitation of BusyBox tr.

BusyBox 1.35.0 tr, which is shipped with Alpine Linux 3.17, does not support
the POSIX [x*n] syntax.

* doc/autoconf.texi (Limitations of Usual Tools): Document limitation of 'tr'
from BusyBox.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 5d5f613e69ae1a51162381364b632c2b3700bee2..b3c708e870b9021ba4cd9eb1cbcc59b2fbd222c4 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -20368,6 +20368,20 @@ $ @kbd{echo abc | coreutils/tr bc d}
 add
 @end example
 
+On platforms with the BusyBox tools, @command{tr} does not support the
+@code{[@var{x}*@var{n}]} option syntax.
+
+@example
+$ @kbd{echo abc | tr 'abcd' '[A*4]'}
+[A*
+$ @kbd{echo abc | coreutils/tr 'abcd' '[A*4]'}
+AAA
+$ @kbd{echo xyz | tr 'a-z' '[A*]'}
+]]]
+$ @kbd{echo xyz | coreutils/tr 'a-z' '[A*]'}
+AAA
+@end example
+
 Posix requires @command{tr} to operate on binary files.  But at least
 Solaris @command{/usr/ucb/tr} and @command{/usr/bin/tr} silently discard
 @code{NUL} in the input prior to doing any translation.  When using