perl one line helper

vasista2k has asked for the wisdom of the Perl Monks concerning the following question:

Hi

I want to replace an IP from a file using perl one liner.
Eg:
The file test.sh has before changing

export SERVING_GW_ADDR=47.104.153.103
export TEMP_SGW_PDP_ADDR=47.104.153.103

I want below result once the command is executed

export SERVING_GW_ADDR=47.104.153.103
export TEMP_SGW_PDP_ADDR=47.104.153.163

In the bove example 47.104.153.103 may not be same always for the variable TEMP_SGW_PDP_ADDR. But the output should be same.

Regards
Vasistha

Comment on perl one line helper

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Re: perl one line helper by ph0enix (Friar) on Dec 07, 2009 at 15:34 UTC
`perl -ne 's/TEMP_SGW_PDP_ADDR=.*$/TEMP_SGW_PDP_ADDR=47.104.153.163/; print $_' < test.sh`	[reply] [d/l]
Re^2: perl one line helper by johngg (Canon) on Dec 07, 2009 at 16:32 UTC
Using the `-p` switch and a positive look-behind will save some typing. I also prefer the safety net of in-place editing with the `-i` switch. `$ cat test.sh some stuff export SERVING_GW_ADDR=47.104.153.103 export TEMP_SGW_PDP_ADDR=47.104.153.103 more stuff $ perl -pi.BAK -e ' > s/(?<=TEMP_SGW_PDP_ADDR=).$/47.104.153.163/;' test.sh $ head -99 test.sh ==> test.sh <== some stuff export SERVING_GW_ADDR=47.104.153.103 export TEMP_SGW_PDP_ADDR=47.104.153.163 more stuff ==> test.sh.BAK <== some stuff export SERVING_GW_ADDR=47.104.153.103 export TEMP_SGW_PDP_ADDR=47.104.153.103 more stuff $` [download] I hope this of interest. Cheers, JohnGG	[reply] [d/l] [select]
Re^2: perl one line helper by happy.barney (Friar) on Dec 07, 2009 at 19:35 UTC
did you heard about switch -p :-) ? Little bit improved version: `perl -pe 's/(?<=TEMP_SGW_PDP_ADDR=).*$/47.104.153.163/'` [download]	[reply] [d/l]
Re^3: perl one line helper by codeacrobat (Chaplain) on Dec 08, 2009 at 19:26 UTC
For more information about -p see perlrun. `print+qq(\L@{[ref\&@]}@{['@'x7^'!#2/"!4']});`	[reply] [d/l]