[Slackbuilds-users] bashisms?

[Andrzej Telszewski]

Hi,

I'm sorry to bother you again, it's not a bashism, but I thought I'll 
share my finding with you.

I have never read my shell's manual (probably applies to all the shells) 
and I was shocked by this behavior, particularly because I spent couple 
of hours debugging my script. I should have read my shell's manual, sigh...

Test script:
#!/bin/sh

AAA=$'\n'$'\n'AAA$'\n'$'\n'

print_aaa() {
   echo "$AAA"
}

echo "$AAA"
echo ======
echo "$(print_aaa)"

OUTPUT:
$ ./test.sh


AAA


======


AAA
$

Basically, command substitution $() removes trailing newlines...
I found it, when I was trying to check MD5 sum of variable, that 
contained 2 trailing newlines at the end.

http://unix.stackexchange.com/questions/17747/why-does-shell-command-substitution-gobble-up-a-trailing-newline-char
http://wiki.bash-hackers.org/syntax/expansion/cmdsubst

Hope this helps.

-- 
Best regards,
Andrzej Telszewski