UNIX for Dummies Questions & Answers

Ok, i've been trying to write some shell scripts. nothing challenging, but just automating

All of the tutorials i read say to start the file with

#!/bin/bash

or whatever your path to bash is.

So i do it, and all of my scripts error out saying ./nameofscript:command not found

when i remove the line completely the script seems to run ok. Why??

I understand the easy answer is to say "so just leave the line out" but I really would like to understand why it's happening.

thanks,
chris

First, read this: What does "#! /usr/bin/ksh" mean?

And then you need to figure out where bash is, if you have it at all. What OS are you using? Run the command "uname -a" and post the results so we know. "echo $SHELL" will probably tell you what shell you are using. Also try:
which bash
which ksh

thanks for that link. apparently I am about 50 steps ahead of myself


uname -a result

Code:

FreeBSD PCBSD.localhost 6.1-RELEASE-p2 FreeBSD 6.1-RELEASE-p2 #1: Thu Jul  6 11:31:02 PDT 2006     root@PCBSD.localhost:/usr/obj/usr/src/sys/PCBSDv1.2  i386

$SHELL result

Code:

/bin/csh

which bash & which ksh

Code:

PCBSD# which bash
/usr/local/bin/bash
PCBSD# which ksh
ksh: Command not found.

thanks for any input / help .. I am eager to code some scripts ..

chris

So you need to use:
#! /usr/local/bin/bash
as the first line of a bash script.

by the way, i suspect the reason your script runs fine without that line has something to do with it running using *your* shell. As above, it's much more sensible to specify the path to a command interpreter explicitly, since then you can specify which command interpreter to use in each script (for example, if you have different scripts that use different command interpreters). Depending on how your system's set up, you'd usually have to type "sh ./nameofscript" or something similar to run a script using an interpreter other than the one specified.