4

we have for example this file

cat exam.txt

I am expert linux man
what we can do for out country
I love redhat machine
"propertie"
centos less then redhat
fedore what
my name is moon yea

we want to add the content of any file as file.txt after properties line

cat file.txt

324325
5326436
3245235
646346
545
643
6436
63525
664
46454

so I try the following:

a=` cat file `

sed -i '/propertie/a  `echo "$a"` ' exam.txt

but not works

any suggestion with sed/awk/perl one liner in order to add content of file after certain string?

expected output

I am expert linux man
what we can do for out country
I love redhat machine
"propertie"
    324325
    5326436
    3245235
    646346
    545
    643
    6436
    63525
    664
    46454
centos less then redhat
fedore what
my name is moon yea
Jeff Schaller
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yael
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1 Answers1

10

You almost never want to store the complete contents of a file in a variable in a Unix shell script. If you find yourself doing that, ask yourself whether there's another solution. If you can't find one on your own, come here and we'll look at it :-)

$ sed '/propertie/r file.txt' exam.txt
I am expert linux man
what we can do for out country
I love redhat machine
"propertie"
324325
5326436
3245235
646346
545
643
6436
63525
664
46454
centos less then redhat
fedore what
my name is moon yea

The r ("read") command in sed takes a filename as its argument and inserts the file's content into the current stream.

If you need the added content indented, then make sure that the content of file.txt is indented before running sed:

$ sed 's/^/    /' file.txt >file-ind.txt
$ sed '/propertie/r file-ind.txt' exam.txt
I am expert linux man
what we can do for out country
I love redhat machine
"propertie"
    324325
    5326436
    3245235
    646346
    545
    643
    6436
    63525
    664
    46454
centos less then redhat
fedore what
my name is moon yea

With ed (calling sed for the indentation of the inserted file). This also does in-place editing of the file and replaces the original with the modified contents.

ed -s exam.txt <<END_ED
/propertie/r !sed 's/^/    /' file.txt
wq
END_ED

The r command in ed is able to read the output of an external command if the command is prefixed with !. We use this to indent the data that we'd like to insert. It is otherwise, for obvious reasons, very similar to the sed solution above.

The only downside with using ed is that you can't generally use it on very large files. sed is for editing streams of undetermined lengths, while ed is ok for editing documents that you could see yourself opening in any other editor, i.e. not files of many megabytes or gigabytes in size.

Kusalananda
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