How delete file from fortran code?

How delete file from fortran code?

I need to delete a file from a Fortran code. I am on ubuntu 12.04, x86_64.
I don't understand why the procedure described below does not work. Please
help me to clarify the situation (actually, on some systems, it works, but
not on mine).
There is another way: I can call directly unix command rm -f file, but I'd
like to know what is wrong with my method. Thank you.
Step 1. make simple script del.sh and put it into ~/bin
$ cat del.sh
[ $# -ge 1 ] && rm -f $1
$ chmod u+x del.sh; mv del.sh ~/bin
Step 2. Fortran code, del.for:
character*100 cmd
character*30 file
call getarg(1,file)
write(cmd,100) file
100 format('source del.sh ',a30)
call system(cmd)
end
Step 3. Compile and run:
$ ifort -o del del.for
$ ./del file
Results:
sh: 1: source: not found
What is wrong? The simple 'source del.sh file' works, but not from Fortran
code... that is confusing.
From the Fortran code:
100 format('del.sh ',a30)
100 format('bash del.sh ',a30)
work perfectly, but
100 format('sh del.sh ',a30)
does not work. I have bash installed, but no csh. Thank you.