replace string in a file with a string from within the same file

Question

I have a file like this (tens of variables) :

PLAY="play"
APPS="/opt/play/apps"
LD_FILER="/data/mysql"
DATA_LOG="/data/log"

I need a script that will output the variables into another file like this (with space between them):

PLAY=${PLAY} APPS=${APPS} LD_FILER=${LD_FILER}

Is it possible ?

fedorqui · Accepted Answer · 2015-05-19 13:11:59Z

3

I would say:

$ awk -F= '{printf "%s=${%s} ", $1,$1} END {print ""}' file
PLAY=${PLAY} APPS=${APPS} LD_FILER=${LD_FILER} DATA_LOG=${DATA_LOG}

This loops through the file and prints the content before = in a format var=${var} together with a space. At the end, it prints a new line.

Note this leaves a trailing space at the end of the line. If this matters, we can check how to improve it.

answered May 19, 2015 at 13:11

fedorqui

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Comments

William Pursell · Accepted Answer · 2015-05-19 13:15:44Z

1

< input sed -e 's/\(.*\)=.*/\1=${\1}/' | tr \\n \ ; echo

answered May 19, 2015 at 13:15

William Pursell

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Interesting expression. Any reason for saying tr \\n \ instead of [more readable] tr "\n" " "?

NeronLeVelu · Accepted Answer · 2015-05-19 13:49:03Z

0

sed 's/"\([^"]*"\)"/={\1}/;H;$!d
x;y/\n/ /;s/.//' YourFile

your sample exclude last line so if this is important

sed '/DATA_LOG=/ d
   s/"\([^"]*"\)"/={\1}/;H;$!d
   x;y/\n/ /;s/.//' YourFile

answered May 19, 2015 at 13:49

NeronLeVelu

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