weird script behaviour

[laplace/d]

i have the following code written on a shell script:

pnt=$(cat /etc/mtab | grep vfat)
pnt_real= ${pnt:0:9}

if i run each line straight on the shell and then 'echo $pnt_real'
i see the correct value. but when i write down the same to lines on gedit as part of a script it gets strange colours:
http://lh6.ggpht.com/_-eMYxH6IV1M/SnnNKoJiOsI/AAAAAAAAAJg/M9zkQNn0U1k/script.png
...and not only that, when i run the script, it doesnt do the job.

is there any other way i can cut the string???
from the line:

/dev/sdb1 /media/disk-1 vfat rw,nosuid,nodev,uhelper=hal,shortname=mixed,uid=10 00,utf8,umask=077,flush 0 0

i only want '/dev/sdb1' or whatever it might say instead of sdb1.

[djurny]

if i understand correctly,


awk '$3=="vfat" { print $1 }' /etc/mtab

will do exactly the same..

what is the shebang you're using?


#!/bin/sh
or

#!/bin/bash
or something else?

[laplace/d]

i am using:

#!/bin/bash
i also tried bin/sh now that u mentioned, but i get the same result.
i even tried your option, which runs beautifuly on the terminal but not on the script

pnt_real= $(awk '$3=="vfat" { print $1 }' /etc/mtab)
but following that line, i echo $pnt_real and nothing, the variable is empty.

[djurny]

i am using:

#!/bin/bash
i also tried bin/sh now that u mentioned, but i get the same result.
i even tried your option, which runs beautifuly on the terminal but not on the script

pnt_real= $(awk '$3=="vfat" { print $1 }' /etc/mtab)
but following that line, i echo $pnt_real and nothing, the variable is empty.

then just use
awk '$3=="vfat" { print $1 }' /etc/mtab
or


#!/bin/bash

awk '$3=="vfat" { print $1 }' /etc/mtab | while read a; do
echo $a
done

# EOF

[geirha]

i am using:


[CODE]pnt_real= $(awk '$3=="vfat" { print $1 }' /etc/mtab)


It's the space between = and $


pnt_real=$(...)

Bash is picky.

Here's how you can do the same in pure bash:


while read fs_spec fs_file fs_vfstype fs_mntops fs_freq fs_passno; do
if [[ $fs_vfstype == "vfat" ]]; then
echo "$fs_spec has filesystem $fs_vfstype and is mounted on $fs_file";
fi
done < /etc/mtab


EDIT: Oh and in case you're wondering, I picked those variable names from fstab's man-page (man fstab). They can of course be replaced by whatever variable names you'd like.

[laplace/d]

you r right, it was the space between = and $. that alone did. as for the second part i didnt understand anything... is there any good tutorial out there some sort of "scripting for dummies" kind of thing, cause the syntax seems quite complicated and confusing.
and finally whats the difference between bash and sh?

[geirha]

I recommend this guide for learning bash: http://mywiki.wooledge.org/BashGuide

As for the difference between /bin/sh and /bin/bash, I think this Wikipedia page explains most of it: http://en.wikipedia.org/wiki/Bourne_shell