ramsdell@LINUS.MITRE.ORG (01/06/90)
bash$ :${abc?abc}
abc: bad substitution
bash$ :${abc?abc}
abc
Process shell exited abnormally with code 1
#### Here is what sh does:
bash$ sh
$ :${abc?abc}
abc: abc
$
------------------------
Johnbfox@sbphy.ai.mit.edu (Brian Fox) (01/06/90)
Posted-Date: Fri, 05 Jan 90 12:40:29 EST
From: ramsdell@linus.mitre.org
Date: Fri, 05 Jan 90 12:40:29 EST
bash$ :${abc?abc}
abc: bad substitution
bash$ :${abc?abc}
abc
Process shell exited abnormally with code 1
#### Here is what sh does:
bash$ sh
$ :${abc?abc}
abc: abc
$
------------------------
John
Uh, I guess this is fixed, since my shell doesn't exit. However, I
changed the output to include the variable name from the left.
Why did you type the ":" in front of everything? Maybe you meant
${abc:?abc}
???
Brianramsdell@LINUS.MITRE.ORG (01/06/90)
Opps! I forgot to say that I am using bash 1.04 with modifications so
that it runs on a NeXT computer. By the way, I like the idea of
having an interactive shell that is programmed as one programs the
shell invoked by the library routine named system.
>> Why did you type the ":" in front of everything? Maybe you meant
The ":" command evaluates its arguments and then ignores the results.
You can use it to make sure that a variable is defined as in:
:${DISPLAY?} # Exit with error when DISPLAY is not defined.
Cryptic, eh?
Johnjacob@gore.com (Jacob Gore) (01/06/90)
/ gnu.bash.bug / ramsdell@LINUS.MITRE.ORG / Jan 5, 1990 / > [...] I am using bash 1.04 with modifications so > that it runs on a NeXT computer The mods from the ftp archives? I get different results: jacob@blackbox> echo $BASH_VERSION 1.04.3 jacob@blackbox> echo $SHLVL 2 jacob@blackbox> bash jacob@blackbox> echo $SHLVL 3 jacob@blackbox> :${abc?abc} abc jacob@blackbox> echo $SHLVL 2 jacob@blackbox> So it prints "abc" and then exits. Jacob -- Jacob Gore Jacob@Gore.Com boulder!gore!jacob