Stefan Viljoen
2018-Jul-27 14:24 UTC
[asterisk-users] SHELL() function Asterisk 13 - can only accept one paramter in string?
With thanks to Ludovic Gasc
---
Turns out there is nothing wrong with the SYSTEM() or SHELL() dialplan functions
in Asterisk 13.22.0.
After several hours of painstaking debugging, the problem turned out to be a
linefeed (\n character, 0x0a hex) in the first parameter passed from Asterisk to
the bash script in the call to the SYSTEM() or SHELL() applications.
Ludovic's suggestion to try AGI revealed the issue - it has nothing to do
with AGI or SYSTEM() but rather my data for one parameter passed through system
containing a linefeed (\n)....
E. g. I was calling this:
same=>n,System(/usr/src/verdi/bash/verdiLogIncomingCall.sh NA
${curIncAccCode} ${sourceChannel} IN ${CHANNEL} ${numbersource}
ApiLogIncomingCall.java 1)
but
${curIncAccCode}
appeared to contain a UUID I generate in a JAVA application.
In fact it contained
uuidtexthere\n
instead of just
uuidtexthere
E. g. it had an appended \n (hex 0a) linefeed character appended.
My script that generated this UUID looked like this:
---
#!/bin/bash
function jsonval {
temp=`echo $jsonResult | sed 's/\\\\\//\//g' | sed
's/[{}]//g' | awk -v k="text"
'{n=split($0,a,","); for (i=1; i<=n; i++) print a[i]}' |
sed 's/\"\:\"/\|/g' | sed 's/[\,]/ /g' | sed
's/\"//g'`
echo ${temp##*|}
}
baseUrl=http://127.0.0.1/api/getVerdiUUID
jsonResult=$(curl --connect-timeout 16 --max-time 32 -s -X GET $baseUrl)
uuid=`jsonval`
echo $uuid
---
So all that I actually needed to fix was to change
echo $uuid
to
echo -n $uuid
and all my problems were solved, SYSTEM() started working perfectly everywhere
in the dialplan as the script wasn't emitting a trailing \n anymore.
So the germane difference between Asterisk 1.8 and Asterisk 13 / 12 / 11 / 10
in this case was that SYSTEM() and SHELL() in the later versions are sensitive
to \n being passed in inside any of the Asterisk variables passed into those
applications' parameter string.
Maybe this helps somebody else.
Regards
Stefan