How to append something to appointed line of ACSII file use command line?

[NiCK_76]

How to append something to appointed line of ACSII file use command line?
For example:
append " 138" to abc.txt must follow "130 131 132 133 134 135 136 137"
original abc.txt
[root@webapp home]# cat abc.txt

130 131 132 133 134 135 136 137


I need execute one or more command under command line to append content of abc.txt.

I wanna abc.txt as following:
[root@webapp home]# cat abc.txt

130 131 132 133 134 135 136 137 138

[Sergejs Svitnevs]

sed s/"137"/"137 138"/ abc.txt

Regards,
Sergejs

[Sergejs Svitnevs]

Ooops, if you want script, simply like this:

sed s/"137"/"137 138"/ abc.txt > abc_changed.txt

mv -f abc_changed.txt abc.txt

Regards,
Sergejs

[NiCK_76]

The abc.txt just a test file. And maybe content differently.
I just knew line number , not content.

[Bojan Nemec]

Nick,

Maybe this script may help (chose your favorite name):


#!/bin/bash
lin=0
while read -e line
do
let "lin += 1"
if [ "$lin" == "$1" ]; then
echo $line$2
else
echo $line
fi
done


Use
# cat abc.txt | script 2 " 138" > newfile

where 2 is line and " 138" is text to append.

Bojan

[Sergejs Svitnevs · Accepted solution]

Example:
line number=2
text to add=138

Script:

sed '2,2 s/$/ 138/' abc.txt > abc_changed.txt
mv -f abc_changed.txt abc.txt