搜索模式，在该行上使用 sed 仅更改文件的第 3 列和第 4 列

Question

Below is the what I have tried

The sed command has to change the 3rd line's 3rd and 4th columns and intent is to change only line starting with sox4d2 .

File content :
 
 sox4d4 ;/appl/m4d4/current ;TEXTMX40 ;TEXTMX40 ;
 sox4d5 ;/appl/m4d5/current ;TEXTMX40 ;TEXTMX40 ;
 sox4d2 ;/appl/m4d2/current ;TEXTMX40 ;TEXTMX40 ;
 
 
 Expected content 
 
 sox4d4 ;/appl/m4d4/current ;TEXTMX40 ;TEXTMX40 ;
 sox4d5 ;/appl/m4d5/current ;TEXTMX40 ;TEXTMX40 ;
 sox4d2 ;/appl/m4d2/current ;TEXTM30 ;TEXTM30 ;
 

I would like to change just the values of 3rd and 4th columns of line 3

Below is the sed I ran but here I am directly searching for string but not the column number:

    sed -i "/sox4d2 /s/TEXTMX40/TEXTM30/g", file.txt

I would like to run this command from perl script actually. Below is the snippet in the perl script, but even here I didn't use the column number:

  my $db_host = "TEXTM30";
  my $ser=srnmain.intranet
  
  system(
    'ssh' => ('-q',$ser),
     sed => ( '-i',qq(/sox4d2/s/\bTEXTMX40\b/$db_host/),$dest_file),
  
  );

Answer 1

With sed how about:

sed -i -E '/sox4d2 /s#([^;]+;[^;]+;)[^;]+;[^;]+#\1TEXTMX30 ;TEXTMX30 #' file.txt

If perl is your option, following will also work:

perl -F' ;' -i -ape '$F[2] = $F[3] = "TEXTMX30" if /sox4d2 /; $_ = join(" ;", @F)' file.txt

Answer 2

With shown samples could you please try following. Written and tested in GNU awk . This should be more Generic solution, give line numbers in line variable, give column names in columns variable and give their respective values in vals variable with comma separated.

awk -v line="3" -v columns="3,4" -v vals="TEXTMX30,TEXTMX30" '
BEGIN{
  num=split(columns,arr1,",")
  num2=split(line,arr3,",")
  for(k=1;k<=num2;k++){
    lines[arr3[k]]
  }
  split(vals,arr2,",")
  for(i=1;i<=num;i++){
    values[arr1[i]]=arr2[i]
  }
}
(FNR in lines){
  for(i=1;i<=NF;i++){
    if(i in values){ $i=";"values[i] }
  }
}
1' Input_file

Answer 3

You may consider this awk :

awk 'BEGIN {FS=OFS=" ;"} $1 == "sox4d2" {$3=$4="TEXTMX30"; $5=""} 1' file

sox4d4 ;/appl/m4d4/current ;TEXTMX40 ;TEXTMX40 ;
sox4d5 ;/appl/m4d5/current ;TEXTMX40 ;TEXTMX40 ;
sox4d2 ;/appl/m4d2/current ;TEXTMX30 ;TEXTMX30 ;