ksh - checking a string for leading # char
ri...@dfwvx1.dallas.geoquest.slb.com
Hi,
I'm working on a flexlm license checker to notify people when their
license is about to expire. I read in a list of license files and I
would like to be able to comment out a file with a # symbol in front
of the file name. Right now I'm doing it with a temp file and grep
but I would think there is a better way with string operations in
ksh. What I need to do is check for a leading # character but I'm
not sure how to do so.
Here is the current code I'd like to fix:
#!/bin/ksh
#
# Read license files and check dates for expiration
#
input=/system/license.files # file containing list of license files
exit_stat=0
node=`hostname`
echo "Subject: License Check on Node " $node
# strip out comment lines in license.files
# (bad design as drops any line with a # anywhere on it)
grep -v "#" $input > /tmp/lic_files
for file in $(< /tmp/lic_files)
do
echo ""
echo "Testing license file " $file
if ! nawk -f /system/licdate.awk $file
then
exit_stat=1
fi
done
rm /tmp/lic_files
exit $exit_stat
--------------
Rick Caldwell
ri...@slb.com
Michael P. Reilly
: Hi,
: done
: rm /tmp/lic_files
: exit $exit_stat
Use a case statement:
for file in $(< $input)
do
case $file in
''|'#'*) ;; # ignore blank lines and comments
*)
echo
echo Testing license file' '$file
nawk -f /system/licdate.awk $file >/dev/null ||
exit_stat=1
;;
esac
done
This lets you add conditions more easily later.
-Arcege
Stephane Du Pasquier
> grep -v "#" $input > /tmp/lic_files
>
> for file in $(< /tmp/lic_files)
> do
you can avoid the temp file:
for file in $(grep ...); do
however, this will fail for big inputs,
so you should rather say:
grep -v '^#' $input|while read file; do
stuff
done
you could also start grep in a co-process:
grep -v '^#' $input |&
and have the loop read from it:
while read -p file; do
I would stay with a grep or sed to filter the
lines; you can use a ksh test to reject every
unwanted line at the top of the loop (by calling a
continue) but it will be slower (provided
your input file is not ridiculously small).
S.
Sharon
Your grep command should be :
grep -v ^# $input > /tmp/lic_files
The "^" is the character which, in regular expressions, stands for "The
line(s) beginning with what follows". By the way, the grep command doesn't
support all of the regular expresions syntax. It does however support the
"^" character.
Sharon Zehavi.
ri...@dfwvx1.dallas.geoquest.slb.com wrote:
> Hi,
>
> I'm working on a flexlm license checker to notify people when their
> license is about to expire. I read in a list of license files and I
> would like to be able to comment out a file with a # symbol in front
> of the file name. Right now I'm doing it with a temp file and grep
> but I would think there is a better way with string operations in
> ksh. What I need to do is check for a leading # character but I'm
> not sure how to do so.
>
> Here is the current code I'd like to fix:
>
> #!/bin/ksh
> #
> # Read license files and check dates for expiration
> #
> input=/system/license.files # file containing list of license files
>
> exit_stat=0
> node=`hostname`
> echo "Subject: License Check on Node " $node
>
> # strip out comment lines in license.files
> # (bad design as drops any line with a # anywhere on it)
>
> grep -v "#" $input > /tmp/lic_files
>
> for file in $(< /tmp/lic_files)
> do
> echo ""
> echo "Testing license file " $file
>
> if ! nawk -f /system/licdate.awk $file
> then
> exit_stat=1
> fi
>
>
> done
>
> rm /tmp/lic_files
> exit $exit_stat
>
> --------------
> Rick Caldwell
> ri...@slb.com
Cal Dunigan
> Your grep command should be :
>
> grep -v ^# $input > /tmp/lic_files
Yep, but any time you have a shell special character (e.g. "^", "#"
etc.) in your command be sure to quote them.
grep -v "^#" $input > /tmp/lic_files
If you aren't sure, use quotes. If they are superflous, they will be
harmless, the converse is not true.
> The "^" is the character which, in regular expressions, stands for "The
> line(s) beginning with what follows". By the way, the grep command doesn't
> support all of the regular expresions syntax. It does however support the
> "^" character.
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Cal Dunigan c...@goodnet.com There is something fundamentally
Consulting wrong with a world in which Ken
Modeling Thompson lives in obscurity and
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