Shell Programming and Scripting

2 21
1 12
3 123
4 1234
6 49
0 49
33 212

I need to replace/increment all the values in the 2nd column that correspond to 0 in the first column.

so for
0 49
i would get
0 50

this can be done through:
paste num4.txt num.txt | grep ^0 | dm x1 x2+1

the most important thing is to preserve this increment in the file which the above command fails to do.

basically i need the completed file looking something like this:
2 21
1 12
3 123
4 1234
6 49
0 50
33 212

what would be the most effective way to go about it...?

thanks!

Hi.

It looks like you are using programs from the suite described by:

Code:

The |STAT Handbook

                   Data Analysis Programs on UNIX and MSDOS

                                 Gary Perlman

If this is the case, did you look at the documentation for dm? ... cheers, drl

Code:

awk '!$1{$2+=1}1' file

thank you for you input.
i tried awk '!$1{$2+=1}1', however it gives me a bunch of errors. problem is that can not decipher the syntax of this awk expression for successful debugging. would you mind clarifying?

paste num.txt num2.txt | awk '!$1{$2+=1}1'

output in terminal:
paste num.txt num2.txt | awk 'num2.txt1{$2+=1}1'
awk: syntax error at source line 1
context is
>>> num2 <<< .txt1{$2+=1}1
awk: bailing out at source line 1


thank you!

It's because you're using csh

Code:

awk '\!$1&&$2++||9' infile

And, of course, you should use gawk, nawk or /usr/xpg4/bin/awk on Solaris.

Edit: Just to clarify - you need to escape the bang (!) only if you're using (t)csh.

given I am using tcsh, and I need to use awk-if command

Basically, logic is as follows -
If some value in column one is equals to 0, then increment the corresponding value in column 2 by one.

What is the correct syntax for this?

Well, did you try my suggestion (to escape the !)?

Actually, you can use this code also:

Code:

awk '$1||$2++' infile

It will miss records like this one though:

Code:

0 0

In that case you'll need:

Code:

awk '$1||++$2' infile

... and it will miss records like this one:

Code:

0 -1

So:

Code:

awk '$1||$2++||"This one works"' infile