Bash Script not printing same output for command when otherwise ran from terminal directly

Question

I am trying to run the same awk command from the script but I get an extra false I am not sure were it is coming from However when i run the command from terminal it does not return false ?

get_state.sh

#/bin/bash

# sed -n '/\\State/{getline; print}' /var/opt/BESClient/besclient.config
export SERVER_STATE=`awk '/\\State/{getline; print $3}' /var/opt/BESClient/besclient.config`
echo $SERVER_STATE
echo $SERVER_STATE
exit 0

Output

./get_state.sh

false Live
false Live

but

sh-4.1$ awk '/\\State/{getline; print $3}' /var/opt/BESClient/besclient.config

Output

Live

why is that an issue ? I am not sure why the false is being printed I am expecting only Live — user3846091
– user3846091, Commented Mar 25, 2015 at 14:59
I didn't look closely enough. I assumed you were asking about the duplication. Sorry. — Etan Reisner
– Etan Reisner, Commented Mar 25, 2015 at 15:02

Wintermute · Accepted Answer · 2015-03-25 15:04:52Z

1

Backslashes need to be escaped in backticks, and some shells also require $ to be escaped in them. Either do that:

#                            vv-- here --------------v
export SERVER_STATE=`awk '/\\\\State/{getline; print \$3}' /var/opt/BESClient/besclient.config`

Or use $() instead:

export SERVER_STATE=$(awk '/\\State/{getline; print $3}' /var/opt/BESClient/besclient.config)

The false comes from the third field of the line after the line that contains State (but not \State), and that they appear on a single line instead of two is because $SERVER_STATE is unquoted in

echo $SERVER_STATE

answered Mar 25, 2015 at 15:04

Wintermute

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1 Comment

Etan Reisner Over a year ago

I was beginning to think about whether DOS newlines could be the problem here but this sounds more plausible. Good catch.

Ed Morton · Accepted Answer · 2015-03-25 15:55:53Z

getline should only be used in a few situations, this not being one of them. In your specific case if \State was the last line of the file or getline failed in any other way then you'd print whatever was the 3rd field of THAT line instead of the subsequent line, and there are various other gotchas. See http://awk.info/?tip/getline for more info.

The way to write your script in awk and call it from shell is:

export SERVER_STATE=$(awk 'f{print $3;f=0} /\\State/{f=1}' /var/opt/BESClient/besclient.config)
echo "$SERVER_STATE"

Note that it doesn't appear to be necessary to export your shell variable and if that's the case then it shouldn't be all-upper-case. Though the variable doesn't appear to be necessary at all so idk what you do with it next...

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