grep s at sign caught as whitespace

Question

I ran into a problem while trying to grep a file that contains the following    abc abc  abc   abc    abc     abc  acb abc  assd dsasd abc     I tried various grep commands  but there was a problem and abc  or  abc were caught as whitespace in my regexps  I want the output  in general  to simulate the following script s output  only the  Good  ones    for res in   grep -F  abc  test txt   do if       res            then echo  res is good  else echo  res is bad  fi  done

User · Answer

After some time with Google I asked on the ask ubuntu chat room.

A user there was king enough to help me find the solution I was looking for and i wanted to share so that any following suers running into this may find it:

grep -P "(^|\s)abc(\s|$)" gives the result I was looking for. -P is an experimental implementation of perl regexps.

grepping for abc and then using filters like grep -v '@abc' (this is far from perfect...) should also work, but my patch does something similar.

User · Answer

No -P needed  -E is sufficient   grep -E      s abc  s       or even without -E   grep        s  abc   s

[regex] grep's at sign caught as whitespace

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