sed to delete a line for a word and line above

cmontr · 07-02-2008, 10:04 PM

Hello guys,

Lets say I have a big file that has text like

o=abc.com
flag=1
o=abcd.com
flag=1
o=abcde.com
flag=1
o=abcdefgh.com
o=abcdef.com
.
.
.

I want to remove every line contains 'flag=1' and a line above it...I used this but got an error machine on solaris machine. ANy ideas please? Thanks again...

sed '/^.* {/ {:a /}/ !{N;ba} }; s/.*flag=1*//' ifile > ofile.txt

Error:
Label too long: /^{/ {:a /}/ !{N;ba} }; s/flag=1//

jschiwal · 07-02-2008, 10:08 PM

I don't think you can use braces in address ranges.

cmontr · 07-02-2008, 10:09 PM

Quote:

Originally Posted by jschiwal

I don't think you can use braces in address ranges.

How would you change it ?

pixellany · 07-02-2008, 10:14 PM

How about something like this:
read a line
send to the hold buffer
read the next line
If it has the desired pattern, then delete it, pull the line from the hold buffer and delete it
then continue

Really good SED tutorial here:
http://www.grymoire.com/Unix/Sed.html

cmontr · 07-02-2008, 10:15 PM

Quote:

Originally Posted by cmontr

How would you change it ?

Tried without them but it wont work...please let me know if you can help..thanks much

cmontr · 07-02-2008, 10:21 PM

Quote:

Originally Posted by pixellany

How about something like this:
read a line
send to the hold buffer
read the next line
If it has the desired pattern, then delete it, pull the line from the hold buffer and delete it
then continue

Really good SED tutorial here:
http://www.grymoire.com/Unix/Sed.html

thanks for the nice link but I couldnt get what I wanted to do yet....please let me know if you can help me with it

ghostdog74 · 07-02-2008, 11:11 PM

Code:

awk 'BEGIN{RS="flag=1"}RT{$NF=""}1' file

cmontr · 07-03-2008, 12:17 AM

Quote:

Originally Posted by ghostdog74

Code:

awk 'BEGIN{RS="flag=1"}RT{$NF=""}1' file

H1 again, ..I tried to fix the syntax but still getting the same error...

awk: syntax error near line 1

Mr. C. · 07-03-2008, 12:41 AM

It works just fine:

Code:

$ cat in
1
2
flag=1
3
4

$ awk 'BEGIN{RS="flag=1"}RT{$NF=""}1' in
1

3
4

Awk has terrible error diagnostics.

ghostdog74 · 07-03-2008, 12:44 AM

Quote:

Originally Posted by cmontr

H1 again, ..I tried to fix the syntax but still getting the same error...

awk: syntax error near line 1

if you are on Solaris, use nawk however RT is not supported ( i believe ). RT is supported by GNU awk. another way is to save each line in array, then go through the array, detecting flag=1, and then delete the one item before. Finally print them out. Have a go at it. good luck

Mr. C. · 07-03-2008, 01:04 AM

Fun with perl too:

perl -e 'undef $/; $_ = <>; s/.*\nflag=1//g; print "$_"' in

cmontr · 07-03-2008, 08:33 AM

Quote:

Originally Posted by Mr. C.

Fun with perl too:

perl -e 'undef $/; $_ = <>; s/.*\nflag=1//g; print "$_"' in

This rules...thanks millions.