Script in c shell

Irmo · 12-15-2004, 04:54 PM

I need a script which if a file contains on first row a string ver.1 change this string to a ver.2.
Whit another word's a script which update the version of file which is written on the first row in file. So if there is a ver.1 it change it to ver. 2, if there is a ver.x it change it to a ver.(x+1). It's not normal that file contains in first row this ver., but my files contains and I need a automatically update.
I'm a beginner in linux :-(.

AnanthaP · 12-15-2004, 04:56 PM

theres a shell command called expr that will help you.

man expr

End

mjrich · 12-15-2004, 04:56 PM

Have a look at Sed and tr - either will probably do what you wish.

Irmo · 12-15-2004, 05:03 PM

the problem is I don't't know how to upgrade the number to a number + 1 (how to read the number from the file) a example of a script will be a help.

mjrich · 12-15-2004, 07:14 PM

Well, it would probably take more than one line for Sed (you could use a modified version of this incrementing script, perhaps).

Otherwise, you could use the venerable Perl, in a similar manner to this post. For example, use something along the lines of perl -pe 's/(ver.)(\d)(.)/$1.($2+1).$3/eg' \ <somefile>.

Cheers,

mj

Irmo · 12-16-2004, 04:14 AM

so this shoud be a script to encreas a number, but have can I change this script that it encraese number in a first row of a file aa.txt. I try to do it for at least 1 hour but I wasn't sucesfull.

#!/usr/bin/sed -f

:d
s/9$_*$$/_\1/
td

# if there aren't any digits left, add a MostSign Digit 0
#
s/^$_*$$/0\1/

# incr last digit only - there is no need for more
#
s/8$_*$$/9\1/
s/7$_*$$/8\1/
s/6$_*$$/7\1/
s/5$_*$$/6\1/
s/4$_*$$/5\1/
s/3$_*$$/4\1/
s/2$_*$$/3\1/
s/1$_*$$/2\1/
s/0$_*$$/1\1/

# replace all _ to 0s
#
s/_/0/g

jlliagre · 12-16-2004, 04:50 AM

There are a bunch of commands that can compute numbers with unix, including expr, bc, dc, awk and modern shells too.
Why using sed alone, which has no clue about numerics ?

Irmo · 12-16-2004, 05:06 AM

Can you pleas write a example of script which find a number in first row of a file and then it increase it by one.

If file look something like this.
aa.txt

sdjgkd 34 lsdfjsdflk
ljsf dfsfj d;fkd fsj
fdk jf 55 5 345

Then I run the script and the file aa.txt whould look like

sdjgkd 35 lsdfjsdflk
ljsf dfsfj d;fkd fsj
fdk jf 55 5 345

(just the 34 will be increased to 35)

jlliagre · 12-16-2004, 02:41 PM

Assuming the numerical field is the second one:

Code:

awk '
NR == 1 {  $2=$2+1 }
{ print $0 }
' aa.txt