writing to a file

Shell Programming and Scripting
1

Hi All.

I have the following simple shell program.

It reads a number from the "/user/amit/bldno";

for example: file "bldno" contains value "100"

After execution of the program the content should change to 101.

---------
#!/usr/bin/tcsh
V= `cat /user/amit/bldno`
echo $V
`rm -rf /user/amit/bldno`
NV = expr $V + 1
echo $NV > /user/amit/bldno
---------------------

It is not writing new value to file "/user/amit/bldn

Could pls help.

Thanks

Amit

---------

2

#!/usr/bin/tcsh
V= `cat /user/amit/bldno`
echo $V
`rm -rf /user/amit/bldno`
NV = expr $V + 1
echo $NV > /user/amit/bldno

You have the wrong shell, tcsh, syntax. Your syntax is Bourne (sh) kile, but backward compatible with Korn (ksh) and Bash (bash).

Examples:

#!/usr/bin/tcsh
set V = `cat /user/amit/bldno`
echo $V
rm -f /usr/amit/bldno
set NV = `expr $V + 1`
echo $NV > /user/amit/bldno

#!/sbin/sh
v=`cat /user/amit/bldno`
echo $v
rm -f /usr/amit/bldno
nv=`expr $v + 1`
echo $nv > /user/amit/bldno

#!/usr/bin/ksh
v=$(cat /user/amit/bldno)
echo $v
rm -f /usr/amit/bldno
nv=$((v+1))
echo $nv > /user/amit/bldno