Shell Programming and Scripting

on linux systems, i can do something like this:

Code:

$ JIOO=hello.one.two
$ 
$ awk -F"." '{print $2}' <<< "${JIOO}"

however, on older systems or other unix systems that dont have the fancy stuff this does not work.

i contemplated using "-v var="${JIOO}" but i dont think that works.

any ideas?

Hello SkySmart,

Not sure about your complete requirement, you could try following code and let me know if this helps you. In case you have any other requirement please do let us know the Input_file and sample output.

Code:

echo ${JIOO} | awk -F"." '{print $2}'
OR
echo $JIOO | awk '{split($0, A,".");print A[2]}'

Thanks,
R. Singh

Why shouldn't that work (with some measures taken)?

Code:

awk -F"." -v var="${JIOO}" 'BEGIN {$0=var; print $2}'
one

There is a portable shell-built-in alternative for that kind of token splitting. It has the side-effect of overwriting your $1 $2 ... argument variables, though. If your shell at least supports functions, putting that in a function should prevent that.

Code:

VAR="a.b.c.d.e"
OLDIFS="$IFS" ; IFS="."
set -- $VAR # Note $VAR must be UNquoted here, we depend on the shell's splitting
IFS="$OLDIFS"

# $1 will be a, $2 b, $3 c, etc.

This may be preferable over using awk repeatedly, since awk is an external programming language, not a shell built-in. Using awk repeatedly to split single lines is like making 9 phone calls to say 9 words, extremely inefficient.

This is not related to the fact you are running on Linux or Unix. The point here is the shell you run. If you run dash on Linux, this command will fail and if you run ksh93 on Unix, it will work as you expect.

Thank you so much. i needed this! i hope this works on older systems!!

---------- Post updated at 03:28 PM ---------- Previous update was at 03:27 PM ----------

thank you
i wanted to avoid using echo. i should have stated that in my original post. sorry.

It's an extremely old syntax, I believe. It works in almost any shell I can throw at it -- including zsh, which isn't even Bourne anymore..