Add prefix and suffix to every line in a .txt file

I am trying to append and prepend text to every line in a .txt file.

I want to prepend: I am a

I want to append: 128... [}

to every line.

Inside of a.txt:

fruit, like
bike, like
dino, like

Upon performing the following command:

$ cat a.txt|sed 'I am a ',' 128... [}'

it does not work how I want it to. I would really want it to say the following:

I am a fruit, like 128... [}
I am a bike, like 128... [}
I am a dino, like 128... [}

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Answers:

Method 1

Method 2

Method 3

Method 4

Answers:

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Method 1

Simple sed approach:

sed 's/^/I am a /; s/$/ 128... [}/' file.txt

^ – stands for start of the string/line
$ – stands for end of the string/line

The output:

I am a fruit, like 128... [}
I am a bike, like 128... [}
I am a dino, like 128... [}

Alternatively, with Awk you could do:

awk '{ print "I am a", $0, "128... [}" }' file.txt

Method 2

sed 's/.*/PREFIX&SUFFIX/' infile

will do, assuming PREFIX and SUFFIX don’t contain any special characters.

&/ (backslash, ampersand and delimiter) are special when in the right hand side of a substitution. The special meaning of those characters can be suppressed by escaping them (preceding them by a backslash) e.g. to prepend A//BC and to append XYZ&& one would run:

sed 's/.*/A//BC&XY\Z&&/' infile

Method 3

Perl:

$ perl -lne 'print "I am a $_ 128... [}"' file 
I am a fruit, like 128... [}
I am a bike, like 128... [}
I am a dino, like 128... [}

More Perl:

$ perl -pe 's/^/I am a /; s/$/ 128... [}/' file 
I am a fruit, like 128... [}
I am a bike, like 128... [}
I am a dino, like 128... [}

And a bit more Perl:

$ perl -lpe '$_="I am a $_ 128... [}"' file 
I am a fruit, like 128... [}
I am a bike, like 128... [}
I am a dino, like 128... [}

For all of these, you can use -i to make the change in the original file:

$ perl -i -lne 'print "I am a $_ 128... [}"' file 
$ perl -i -pe 's/^/I am a /; s/$/ 128... [}/' file 
$ perl -i -lpe '$_="I am a $_ 128... [}"' file

Method 4

Alternative sed

sed -e 's/^(.*)$/I am a 1 128 [{/

It searches for everything .* between the start ^, and end of line $, and places it in a group ( ). It then replaces it with the prefix, the (first) group 1, and the suffix.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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