How can I change file value based on condition

Shell Programming and Scripting
1

Hi, Gurus,
I got a problem to resolve following issue:
I have one file file1as following:

[title1]
start_dt=2010-01-01 12:00:02
[title2]
start_dt=2011-01-01 09:00:02
[title3]
start_dt=2009-01-01 11:00:02

I have another file file2 as following:

title1, 2010-01-03 10:00:02
title2, 2011-01-04 11:00:02
title3, 2009-02-04 13:00:02

I need replace file1's start_dt value with file2's value based on title value. final file should like following:

[title1]
start_dt=2010-01-03 10:00:02
[title2]
start_dt=2011-01-04 11:00:02
[title3]
start_dt=2009-02-04 13:00:02

:wall:

Could any one among you may able to help please ?

Thanks in advance

2

this would be what you need:

  awk -F, 'NR==FNR{ a["["$1"]"]=$2} NR>FNR{ if($0 in a){ f =1;i=$0; print $0; next;}else{ $0 = "start_dt="a; print $0; f=0;i=0; } }' file2 file1

output:

[title1]
start_dt= 2010-01-03 10:00:02
[title2]
start_dt= 2011-01-04 11:00:02
[title3]
start_dt= 2009-02-04 13:00:02
3

The solution will not work for the following data:

File1:

[title1]
start_dt=2010-01-01 12:00:02
[title2]
start_dt=2011-01-01 09:00:02
[title3]
start_dt=2009-01-01 11:00:02
[title9]
start_dt=2011-01-01 07:00:02

File2:

title2, 2010-01-03 10:00:02
title3, 2011-01-04 11:00:02
title7, 2009-02-04 13:00:02
4

Thanks, sk1418,
after I change awk to nawk (since my OS is sun sparc) it works perfectly.

5

OK, corrected version comes:

awk -F, 'NR==FNR{ a["["$1"]"]=$2} 
NR>FNR{ if($0 in a){ 
f =1;i=$0; print $0; next;      }
if(f==1&&i){ 
        $0 = "start_dt="a; 
        print $0; f=0;i=0; }else print $0 }' file2 file1

output based on your example:

[title1]
start_dt=2010-01-01 12:00:02
[title2]
start_dt= 2010-01-03 10:00:02
[title3]
start_dt= 2011-01-04 11:00:02
[title9]
start_dt=2011-01-01 07:00:02
6 
nawk 'BEGIN {
   while (getline < "./file1" > 0)
      if ($0 ~ "title") {
         gsub("\[|\]","",l=$0)
         x[l]=$0
         while (getline s < "./file1" > 0)
            if (s ~ "start_dt=") {
               split(s,a,"=")
               y[l] = a[1]
               z[l] = a[2]
               break
            }
      }
} {
   FS=", "
   if ($1 in x)
      printf("%s\n%s=%s\n", x[$1],y[$1],$2)
}' ./file2