UNIX for Dummies Questions & Answers

Hello

I am using a grep command with two patterns in my KSH script. File has line breaks in it and both the patterns are in different lines. Here is the command grep -l 'RITE AID.*ST.820' natriter820u.20140914

Pattern1 - RITE AID
Pattern2 - ST*820

I am not getting any results from this, whereas if I replace this file with a different file having no line breaks then it works. Is there any work around to deal with line breaks here.

Here is the sample data:-

Code:

ISA*00* 00 *ZZ*NATIONSBANK *14*0030020520500 *140918*1200*U*00401*000006436*0*P*^ 
GS*RA*014578892*IGIHCJEEJ*20140918*1200*6442*X*004010
ST*820*000006482 
N1*PR*RITE AID HDQTRS. CORP.*1*014578892

Can someone please help.

Thanks

Your grep command will not print the sample's filename as it is looking for "RITE AID" coming in front of "ST.820" which will not be the case even with newlines removed.

However, grep does not match patterns across line boundaries, so either remove those (e.g. tr -d '\n') or use other methods, e.g. awk to match either pattern and print the FILENAME when both are found.

grep does not work that way. grep matches lines containing patterns, it does no logic like 'if this line and this line do this thing or this other thing' etc. It's not a programming language.

awk is a programming language, and can.

Code:

$ awk -v P1="pattern1" -v P2="pattern2" '
# set A if P1 found, set B if P2 found
$0~P1{A=1} $0~P2{B=1} 
# If filename changes, and A set, and B set, print filename.  Reset A and B.
(L != ARGIND) { L++; if(A && B) print ARGV[L];  A=B=0 }
# Check A and B for the last filename and print.
END { if(A&&B) print ARGV[L] }' filename1 filename2 filename3 filename4

Thanks Rudic, I will correct the first mistake here also I am very new to Unix, will it be possible for you to provide me the with the right command that you think should work with tr -d '\n'

Code:

tr -d '\n' <file | grep ST*820.*RITE AID

Thanks, I will try and see if it works.. my company is using a pretty old version so I have a limited number of possibilities

---------- Post updated at 03:37 PM ---------- Previous update was at 03:33 PM ----------

Thanks a lot, I tried tr -d '\n' <natriter820u.20140914 | grep 'ST.820.*RITE AID'

and it gave me the content of the file but I need to get the file name so I tried
tr -d '\n' <natriter820u.20140914 | grep -l 'ST.820.*RITE AID'

It is giving a weird output of <stdin>

These days, even a wireless router probably has awk. If you're running anything with Linux or UNIX in its name you should have it.

grep prints '<stdin>' because you didn't give it a file name, it was reading from tr instead, through a pipe, also called 'standard input'. So that's not quite what you want.

grep usually has limits on how long a line it will process, and tr -d '\n' turns it into one giant line, so that's not a good solution anyway.

There are ways with grep, involving calling grep multiple times, and possibly sorting and merging its output. I think the awk way is the closest to what you asked for.