[SOLVED] Calling a Shell script from inside a Shell script

manyrootsofallevil · 07-06-2012, 10:36 AM

I got roped in to help a colleague at work and I'm a total bash newbie. I'm trying to invoke a script from inside another script

Here are the scripts:

test.env

Code:

echo Works!

delete_correspondence.sh

Code:

#!/bin/sh 
sh test.env
..
echo "Batch Process finished at `date`"

The problem is that test.env doesn't run from inside delete_correspondence.sh

Code:

sh -x delete_correspondence.sh
+ sh $'test.env\r'
: No such file or directory

I've also tried with the full path to test.env but to no avail.

This is not a homework question, test.env will set up the environment variables but my colleague doesn't have that information yet, not sure why.

Oddly enough, for me anyway, this works. In other words, it displays Works! in a loop

Code:

echo Works!
sh test.env

Any ideas?

TIA

MensaWater · 07-06-2012, 11:36 AM

Don't run "sh test.env" - just make test.env executable and run "test.env".

ntubski · 07-06-2012, 03:24 PM

Quote:

Originally Posted by manyrootsofallevil

Code:

sh -x delete_correspondence.sh
+ sh $'test.env\r'
: No such file or directory

\r indicates a carriage return; windows/dos uses \r\n to indicate end of line, but unix uses only \n. You can convert to unix line endings with unix2dos (aka u2d), or with any decent text editor.

Reuti · 07-07-2012, 09:10 AM

As the purpose is to set environment variables, it’s necessary to source the test.env instead of executing it. Otherwise they are set in subshell only and vanish on return. Either of:

Code:

source test.env
. test.env

manyrootsofallevil · 07-09-2012, 02:47 AM

Removed the shebang and it works fine now. I guess it was getting confused between default shell (BASH) and Bourne shell.

with #!/bin/sh

Code:

sh delete_correspondence.sh

and

Code:

./delete_correspondence.sh

don't work

Code:

bash delete_correspondence.sh

does work

without #!/bin/sh

Code:

sh delete_correspondence.sh

doesn't work

Code:

bash delete_correspondence.sh

and

Code:

./delete_correspondence.sh

do work

Code:

./delete_correspondence.sh

@Reuti

The script was originally running with

Code:

. test.env

, we just changed it to test things out (i.e. in desperation)

pan64 · 07-09-2012, 05:49 AM

No, shebang or "it" was never confused, the OS (or shell) always knows what to do and how to do. I think you are confused because you do not know what happened.

when you explicitly defines the shell (so executes: <interpeter> <scriptname>) the shebang has no effect - or maybe the flags of the shebang has some influence in some cases. So sh delete_correspondence.sh will use sh and it does not work, bash delete_correspondence.sh works.
When you execute the script itself without defining the interpreter the shebang interpreter will be executed (if exist) instead of the script and that interpreter will process the script. So using #!/bin/sh will execute sh delete_correspondence.sh again which fails. Without shebang the current interpreter/shell will be invoked to process the script. Finally, in your last example (using source or . ): . delete_correspondence.sh the current actual shell will process the script without invoking any other shell therefore the shebang has no meaning in this case again.

The root cause of your problem is probably the \r which was already mentioned, you need to remove it. bash could handle it (silently ignored), but sh assumed this is still part of the filename and could not find the file. Probably you edited this file under windows?

manyrootsofallevil · 07-10-2012, 01:56 AM

Quote:

Originally Posted by pan64

The root cause of your problem is probably the \r which was already mentioned, you need to remove it. bash could handle it (silently ignored), but sh assumed this is still part of the filename and could not find the file. Probably you edited this file under windows?

It was edited using a windows x-windows client, which must add the \r.

I made the changes on a different box, using Putty, which would explain why it works.

Thanks

Reuti · 07-10-2012, 04:42 AM

Quote:

Originally Posted by manyrootsofallevil

It was edited using a windows x-windows client, which must add the \r.

I assume you mean “using a windows x-windows server” and started a client application on the Linux machine. Which graphical application did you use? I assume that using x-windows would hide the platform dependent behavior.