PATTERN MATCHING PROBLEM

[sachrath]

Hi All,

I have a file in UNIX with 3 fields in it
A ,B C with their names.

I would like to search for all the values in the file for which
A is NULL and B is not NULL
and
again
A is NOT NULL and B is NULL .

NULL refers to a blank value within the delimiters which is '|' in this case.

Any help is appreciated.

Thx
Sachin

 

[PHV]

If NULL refers to an empty field:
awk -F'|' '($1=="" && $2!="") || ($1!="" && $2=="")}' /path/to/file
If NULL refers to a blank field:
awk -F'|' '($1==" " && $2!=" ") || ($1!=" " && $2==" ")}' /path/to/file

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[sachrath]

Thx ,

We have some standard UNIX scripts prepared which works only with EGREP , so I need to pass the search criterion in PATTERN MATCH.

The characters like '=' & '!=' doesnt work in pattern match .

Thx
Sachin Rath.

 

[PHV]

A is NULL and B is not NULL
'^ *\|[^ |]'
A is NOT NULL and B is NULL
'^[^ |]+\| *\|'

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[sachrath]

Hi PHV,

Thx once again , it is working , but could not understand why '+' is used within the search string.
Chao
Sachin

 

[PHV]

+ means at least one occurrence of preceding expression.

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244