> Running: > > #!/bin/sh > set -ex > > for p in ad2 ad0 ad1 > do > a0=`expr $p : '^ad\([0-9]\)$'` > done > > I get: > > syv# sh _ > + expr ad2 : ^ad\([0-9]\)$ > + a0=2 > + expr ad0 : ^ad\([0-9]\)$ > + a0=0 > syv# echo $? > 1
The `set -e' says to exit the shell if a simple command fails. POSIX.2 says that the exit status of an assignment statement without an accompanying command is either 0 or the exit status of the last command substitution performed while expanding the rhs. `expr' returns 1 when the result is `0'. Thus the assignment statement fails and the shell exits. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ( ``Discere est Dolere'' -- chet ) Chet Ramey, ITS, CWRU [EMAIL PROTECTED] http://cnswww.cns.cwru.edu/~chet/ To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
