Asterisk cmd Backticks

Synopsis:

Execute a shell command and save the result as a variable.

Description of application:

Backticks(<VARNAME>|<command>)

<VARNAME> – The name of the variable to be set.
<command> – The shell command to execute; be sure to provide the full path to the command. I used sh, but I think any language will do.

Description of function:

Backticks(<command>)

<command> – Same as above.

Notes

• *CLI> show application BACKTICKS
• *CLI> show function BACKTICKS

This application is not distributed as part of Asterisk.

Return value

Returns the resulting string.

Example

• application:

exten => s,1,BACKTICKS(FOO|/your/path/command.sh) ; sets FOO to result

• function:

exten => s,1,Set(FOO=${BACKTICKS(/your/path/command.sh ${arg1} ${arg2})}) ; sets FOO to result, I only could get the “function” to take arguments

• command.sh:

#!/bin/sh
x=0
if [ -e “/some/path/$1/caller-$2.ulaw” ]; then x=1; fi /* see man test for info on the if argument */
echo $x

The above takes two args, checks for the existence of the file, if it exists return 1, else return 0; i.e. the resulting value of foo.

install

Follow his install instructions except:

1. you may want to save app_backticks.c to /usr/src/asterisk
2. for his step 3, cd /usr/src/asterisk first and then execute /usr/src/asterisk/contrib/scripts/astxs -install app_backticks.c

This script doesn’t work with asterisk >= 1.8 .

See also

• Asterisk func shell – A similar functionality as an Asterisk function
• Asterisk cmd System
• Asterisk func exists
• Asterisk variables
• Asterisk functions

• Asterisk – documentation of application commands