Re: bash scripting

John Kelly
2004-08-14T12:36:41Z

Hi,
On Fri, 13 Aug 2004 23:35:14 -0700
"" <dave@dpomeroy.com> wrote:

>
>
> I wrote the following script to learn to read and write files. No
> matter how I try to start it it doesn't work.
>
> #!/bin/bash
>
> shopt -s -o nounset
>
> declare LINE
>
> exec 3< test.dat
>
> while read LINE <&3 ; do
> printf "%s\n" "$LINE"
> done
>
> exit 0
>

I copied this into a file and it runs fine on my Debian system. I
think your error message gives a hint.

> this is the error
>
> [root@localhost scripts]# ./test.sh
> : bad interpreter: No such file or directory
> [root@localhost scripts]#
>
: bad interpreter: No such file or directory

Usually means that the system can't find the interpreter. ie when it
looks at the line:#!/bin/bash
it can't find /bin/bash.
I have seen similiar problems with perl. Someone puts
#!/bin/perl
in a script. It works on one machine but if the script is moved to
another machine, it bombs out because the perl interpreter is in a
different place.

I assume bash is on your system. Try running
which bash
to find the path to the bash excutable. On most Linux systems it is
/bin/bash but I have seen /usr/local/bin/bash and /opt/bin/bash (on a
Solaris system).

Incidently, my standard way of writing scripts in vi is to type
#!
Then type <ESC>
Then type : r ! which bash
This causes the path to bash appear on the line under the #! line.
I then move the cursor up one line and type J to join the lines.
This guarantees the correct path to the interpreter on the machine I
am using. But then you may not be using vi :-)

Hope this helps.

regards,

John Kelly