Simple Scripting Problem [Comparison of several strings]

thomasknowles · 07-21-2008, 08:26 AM

Greetings everyone,

First of all I am a first time poster, so "hello", second of all I have a problem, I have been scratching my head and "Googling" for quite some time but still can't find an adequate or reasonably simple solution for my problem.

I have a file and it is delimited by tabs as seen below tabs:

## Short segmentation

Code:

AddTimers	icq.c	root/modules/icq	->	KeepAlive	icq.c	root/modules/icq
AddTimers	icq.c	root/modules/icq	->	SelectServer	icq.c	root/modules/icq
AddTimers	icq.c	root/modules/icq	->	eb_timeout_add	plugin_api.c	root/src
Connect_Remote	send.c	root/modules/icq/libicq	->	ICQ_Debug	libicq.c	root/modules/icq/libicq
Connect_Remote	send.c	root/modules/icq/libicq	->	proxy_connect	libproxy.h	root/libproxy
Connect_Remote	send.c	root/modules/icq/libicq	->	proxy_gethostbyname	libproxy.h	root/libproxy
Connect_Remote	send.c	root/modules/icq/libicq	->	set_nonblock	tcp.c	root/modules/icq/libicq
Connect_Remote	send.c	root/modules/icq/libicq	->	strdup	yahoo_util.h	root/modules/yahoo2/libyahoo2
ayttm-0.2.2	Connect_Remote	send.h	root/modules/icq/libicq	->	ICQ_Debug	libicq.c	root/modules/icq/libicq

If you're asking yourself what the devil that is, it's just a break down of an early version of ayttm, but I digress, this is what I want to do. I wish to match the three strings e.g. (AddTimers icq.c root/modules/icq) on the left hand side of the -> against the three strings on the right hand side of the -> and if they match, remove the entire line.

There are numerous ways I have attempted this, however, due to my lack of competence in bash scripting and regular expressions (I am working on it) both of which have contributed towards my demise. I am not asking for an answer, I will never learn that way, but just a simple push in the right direction.

Thank you for reading.

Thomas Knowles.

edit.

Code:

grep -Ev '^(.+)\s*->\s*\1$' file

submitted by radoulov

Example use

Code:

AddTimers	icq.c	root/modules/icq	->	KeepAlive	icq.c	root/modules/icq
AddTimers	icq.c	root/modules/icq	->	SelectServer	icq.c	root/modules/icq
AddTimers	icq.c	root/modules/icq	->	eb_timeout_add	plugin_api.c	root/src
Connect_Remote	send.c	root/modules/icq/libicq	->	ICQ_Debug	libicq.c	root/modules/icq/libicq
Connect_Remote	send.c	root/modules/icq/libicq	->	proxy_connect	libproxy.h	root/libproxy
yyparse	plural.c	root/intl	->	new_exp_1	plural.c	root/intl
yyparse	plural.c	root/intl	->	new_exp_2	plural.c	root/intl
yyparse	plural.c	root/intl	->	new_exp_3	plural.c	root/intl
yyparse	plural.c	root/intl	->	yyparse	plural.c	root/intl
AddTimers	icq.c	root/modules/icq	->	AddTimers	icq.c	root/modules/icq

Returned values when applying the grep.

Code:

AddTimers	icq.c	root/modules/icq	->	KeepAlive	icq.c	root/modules/icq
AddTimers	icq.c	root/modules/icq	->	SelectServer	icq.c	root/modules/icq
AddTimers	icq.c	root/modules/icq	->	eb_timeout_add	plugin_api.c	root/src
Connect_Remote	send.c	root/modules/icq/libicq	->	ICQ_Debug	libicq.c	root/modules/icq/libicq
Connect_Remote	send.c	root/modules/icq/libicq	->	proxy_connect	libproxy.h	root/libproxy
yyparse	plural.c	root/intl	->	new_exp_1	plural.c	root/intl
yyparse	plural.c	root/intl	->	new_exp_2	plural.c	root/intl
yyparse	plural.c	root/intl	->	new_exp_3	plural.c	root/intl

radoulov · 07-21-2008, 11:17 AM

Code:

grep -Ev '^(.+)  *->  *\1$' file

pixellany · 07-21-2008, 11:51 AM

Your example does not include any lines that meet your criteria...

Watch out for spaces and tabs. eg radulov's code might not work based on whatever non-printing characters follow the "->" (or are embedded in the string to be matched).

ghostdog74 · 07-21-2008, 12:34 PM

Code:

awk '/AddTimers/ && $1==$5 && $2==$6 && $3==$7' file

thomasknowles · 07-21-2008, 03:08 PM

Thank You for your replies.

radoulov · 07-21-2008, 03:44 PM

Quote:

Originally Posted by pixellany

Your example does not include any lines that meet your criteria...

Watch out for spaces and tabs. eg radulov's code might not work based on whatever non-printing characters follow the "->" (or are embedded in the string to be matched).

Yep,
perhaps something like this will be more appropriate:

Code:

grep -Ev '^(.+)\s*->\s*\1$' file

thomasknowles · 07-22-2008, 03:17 AM

Quote:

Originally Posted by radoulov

Yep,
perhaps something like this will be more appropriate:

Code:

grep -Ev '^(.+)\s*->\s*\1$' file

Thank You,

this solution worked absolutely perfectly, I apologise about my ambiguity of my problem description but I see you thwarted that nicely. You have just made my day ten times better.

Thomas Knowles.

pixellany · 07-22-2008, 06:53 AM

Any time that we can "thwart ambiguity", that is a GOOD THING.....