On 10:55 13 Jun 2003, David Kramer <[EMAIL PROTECTED]> wrote:
| On Friday 13 June 2003 04:40 am, Matthew Richards wrote:
[...]
| > but I do not know how to determine if the string "serial" exists in the
| variable SMOUSE in terms of the 'if' statement.
|
| The answer is.... you don't.
|
| If you specify the -q option, grep will exit immediately with zero status if
| any match is found (even if an error was detected), or non-zero if no match
| is found. The $? shell variable is always set to the exit code of the
| previous command, so just check that.
|
| /bin/grep -qi "serial" /etc/sysconfig/mouse
| if [ $? != 0 ]; then
| echo "There is not a serial mouse attached to this system."
| else
| echo "A serial mouse is attached to this system."
| fi
Of course, because grep (and many other command) act as boolean tests,
and if's condition test _is_ a command, a much more readbale idom is this:
if /bin/grep -qi "serial" /etc/sysconfig/mouse
then
echo "A serial mouse is attached to this system."
else
echo "There is not a serial mouse attached to this system."
fi
No ugly poking at $? required.
Cheers,
--
Cameron Simpson <[EMAIL PROTECTED]> DoD#743
http://www.cskk.ezoshosting.com/cs/
The impossible we understand right away - the obvious takes a little longer.
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