Can't find the mistake in sed expression

chebarbudo · February 16, 2009, 9:07am

Hi there,
Can anyone help me find the correct expression for sed.
I want to repace iface eth0 inet wathever
with iface eth0 inet static

Thanks for your help
Santiago

Franklin52 · February 16, 2009, 9:16am

Try:

sed 's/\(iface eth0 inet\).*/\1 static/'

Regards

pludi · February 16, 2009, 9:18am

sed '/^iface eth0 inet / s/^\(iface eth0 inet\).*/\1 static/' /etc/network/interfaces

A back reference is always only valid within the substitution and can't be kept across commands.

danmero · February 16, 2009, 9:27am

sed '/iface eth0 inet/s/\(.*\) .*$/\1 static/' file

vgersh99 · February 16, 2009, 9:30am

$ echo 'iface eth0 inet wathever foo' | sed '/^iface eth0 inet / s/^\(iface eth0 inet\).*/\1 static/'
iface eth0 inet static

$ echo 'iface eth0 inet wathever foo' | sed '/^iface eth0 inet / s/^\(iface eth0 inet\) *\([^ ][^ ]*\) *\(.*\)/\1 static \3/'
iface eth0 inet static foo

chebarbudo · February 16, 2009, 4:23pm

Thanks Franklin52, pludi, danmero and vgersh99.
pludi is right when he says: