pattern matching

nram_krishna · July 25, 2011, 7:22am

How should i use sed command to replace a pattern of multiple occurrences with space. how to make this text -asadjh--nfkdjnf------nfjksnfjkd as <space>asadjh<space> nfkdjnf<space>nfjksnfjkd

Thanks in advance!

bartus11 · July 25, 2011, 7:23am

Try:

sed 's/-+/ /g' file

michaelrozar17 · July 25, 2011, 7:29am

echo '-asadjh--nfkdjnf------nfjksnfjkd'|tr -s '-' ' '

Skrynesaver · July 25, 2011, 7:39am

Could someone with sed knowledge clear up why this is the case?

skrynesaver@busybox:~$ echo '-asadjh--nfkdjnf------nfjksnfjkd'|perl -e '$_=<STDIN>; s/(.)\1+/ /g;print'
-asadjh nfkdjnf nfjksnfjkd
skrynesaver@busybox:~$ echo '-asadjh--nfkdjnf------nfjksnfjkd'|sed 's/\(.\)\1+/ /g'
-asadjh--nfkdjnf------nfjksnfjkd

Hmmn sed -r works correctly (GNU sed)

michaelrozar17 · July 25, 2011, 7:49am

Skrynesaver:

Could someone with sed knowledge clear up why this is the case?


skrynesaver@busybox:~$ echo '-asadjh--nfkdjnf------nfjksnfjkd'|perl -e '$_=<STDIN>; s/(.)\1+/ /g;print'
-asadjh nfkdjnf nfjksnfjkd
skrynesaver@busybox:~$ echo '-asadjh--nfkdjnf------nfjksnfjkd'|sed 's/\(.\)\1\+/ /g'
-asadjh--nfkdjnf------nfjksnfjkd

Hmmn sed -r works correctly (GNU sed)

In GNU Sed you would need to escape the sign + in order to work.