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if: Expression syntax error in csh if statement

I've got a simple csh script that checks for the exit code of grep and echos the result:

Code:

#!/bin/csh



if (df -k | /usr/xpg4/bin/grep -q /mnt/Backup == 0) then



        echo 'Mount worked'

else

        echo 'Mount failed'

endif

Unfortunately I keep getting: if: Expression syntax
Can anyone see what's wrong with it?

Quote:

Originally Posted by Mark_667 (Post 4706842)

I've got a simple csh script that checks for the exit code of grep and echos the result:

Code:

#!/bin/csh



if (df -k | /usr/xpg4/bin/grep -q /mnt/Backup == 0 ) then



        echo 'Mount worked'

else

        echo 'Mount failed'

endif

Unfortunately I keep getting: if: Expression syntax
Can anyone see what's wrong with it?

The problem is in your check/compare statement:

Code:

(df -k | /usr/xpg4/bin/grep -q /mnt/Backup == 0)

There needs to be just one value to each side of the compare symbol (in this case, "==").

Try this:

Code:

#!/bin/csh



if ( `df -k | /usr/xpg4/bin/grep -q /mnt/Backup` == 0) then



        echo 'Mount worked'

else

        echo 'Mount failed'

endif

Thanks, that solved that problem, unfortunately I'm coming across more strangeness.
The script says the mount failed but it's definitely listed in the df output:

Code:

{root}: CheckMount.sh

Mount failed

{root}: df -k

Filesystem            kbytes    used  avail capacity  Mounted on

/dev/dsk/c0t0d0s0    21268609 3865380 17190543    19%    /

/proc                      0      0      0    0%    /proc

fd                        0      0      0    0%    /dev/fd

mnttab                    0      0      0    0%    /etc/mnttab

swap                2091208      24 2091184    1%    /var/run

swap                2091200      16 2091184    1%    /tmp

/dev/dsk/c0t0d0s7    15120459 2131387 12837868    15%    /export/home

<BackupServer>:/Solaris_Backups/<Solaris box>

                    2930134008 2499720736 430413272    86%    /mnt/Backup

Running the if statement outside of the script gives:

Code:

{root}: `df -k | /usr/xpg4/bin/grep -q /mnt/Backup`

usr/ucb/: Permission denied

{root}: su

# `df -k | /usr/xpg4/bin/grep -q /mnt/Backup`

: Command not found

# /usr/xpg4/bin/grep

Usage:  grep [-E|-F] [-c|-l|-q] [-bhinsvwx] [file ...]

grep [-E|-F] [-c|-l|-q] [-bhinsvwx] -e pattern... [-f pattern_file]...[file...]

grep [-E|-F] [-c|-l|-q] [-bhinsvwx] [-e pattern]... -f pattern_file [file...]

#

if you run

Code:

# `something`

then you're trying to run the *output* of the command, not just running the command, see? If you try running something simple...

Code:

# `echo ls`

then you'll see that the echo command prints out the result "ls" but being in backticks it then proceeds to run ls itself... yes?

How about just running the command and then testing the error code:
<command>
if [ $? ] then <do something>; else <do something else>; endif

Also, outside the syntax issue - why use df to check if something is mounted rather than just using mount?

The below will also work for csh:

Code:

#!/bin/sh

mount | grep "/mnt/Backup" > /dev/null 2>&1 && echo "It's mounted" || echo "Not there"

So far I've got:

Code:

#!/bin/csh



set isMounted = 'Not Mounted'

mount | grep /mnt/Backup >& ./IsMounted.log



set isMounted = `wc -l ./IsMounted.log`



if(isMounted == '1 ./IsMounted.log') then

        echo 'Mount worked'

        echo $isMounted

else

        echo 'Mount failed'

        echo $isMounted

endif

which outputs:

Quote:

Mount failed
1 ./IsMounted.log

I don't understand how it's failing the equality test. I'd also like to be able to do it without having to redirect output to another file and count in the lines but this is the only way I can get it to work at the moment.

dayid, your code gives:
Ambiguous output redirect
I think it's the '2>&1' but changing this to the more csh friendly >& gives 'Missing name for redirect'?

So you tried it w/o the data redirects also, right?

Code:

#!/bin/csh

mount | grep "/mnt/Backup"  && echo "It's mounted" || echo "Not there"

Quote:

So you tried it w/o the data redirects also, right?

Ahh, I didn't know you could do that. I eventually settled on this:

Code:

#!/bin/csh



set isMounted = false



mount | grep "/mnt/Backup" && set isMounted=true || set isMounted=false



if($isMounted == 'true') then

        echo 'Mount worked'

        echo $isMounted

else

        echo 'Mount failed'

        echo $isMounted

endif