Tiny Core Linux

General TC => Programming & Scripting - Unofficial => Topic started by: sbp on May 21, 2014, 04:10:48 PM

Title: need help on reading each line from a file into a separate variable
Post by: sbp on May 21, 2014, 04:10:48 PM

Hi I need help in making a script where I will read from a txt file.
In this file each line should be read and saved as a new variable like var1, var2 etc.


I have tried this code:

Code: [Select]

#!/bin/sh
while read LINE
do
var1=$(echo $LINE)
echo $var1
var
done < FILE.txt

This will read the file (FILE.txt) and list the content of each line on the screen, but I need to assign each line to a new variable.

The content of FILE.txt

Code: [Select]

CONTENT_A
CONTENT_B
CONTENT_C
etc

And the output I would like would be:
var1=CONTENT_A
var2=CONTENT_B
var3=CONTENT_C
etc..


Thanks
Steen

Title: Re: need help on reading each line from a file into a separate variable
Post by: gerald_clark on May 21, 2014, 04:32:10 PM

Try a bash forum.
What you want to do is extremely difficult.

Title: Re: need help on reading each line from a file into a separate variable
Post by: Lee on May 21, 2014, 05:24:41 PM

The following seems clumsy, but it works.  I hate having to use temp files, but I suspect there's a more elegant way.

Code: [Select]

# create a data file for testing
echo -e "Value A\nValue B\nValue C" >/tmp/datfile

# initialize the variable part of the variable name
VARVAR=0

# read the data and write a temp file
cat /tmp/datfile |while read X ; do {
  echo "VAR${VARVAR}=\"${X}\"" >>/tmp/dotme
  VARVAR="`expr ${VARVAR} + 1`"
} done

# source the temp file
. /tmp/dotme

# demonstrate that it worked
echo -e "VAR0=${VAR0}\nVAR1=${VAR1}\nVAR2=${VAR2}"


Title: Re: need help on reading each line from a file into a separate variable
Post by: Greg Erskine on May 21, 2014, 09:33:38 PM

Another temp file fudge using your input file format.

Code: [Select]

awk '{ print "var"NR"="$0 }' FILE.txt > temp.sh && . temp.sh
regards

Title: Re: need help on reading each line from a file into a separate variable
Post by: Rich on May 21, 2014, 09:53:51 PM

Hi sbp
If you provided some more details on exactly what you are trying to do, someone might be able to offer a better solution. In the mean
time, try doing a Google search for:

Code: [Select]

linux script dynamic array

Title: Re: need help on reading each line from a file into a separate variable
Post by: sbp on May 22, 2014, 01:31:18 PM

Quote from: Greg Erskine on May 21, 2014, 09:33:38 PM

Another temp file fudge using your input file format.

Code: [Select]

awk '{ print "var"NR"="$0 }' FILE.txt > temp.sh && . temp.sh
regards

Hi Greg

Thank you for your suggestion it is working fine. I need it for allowing update of piCorePlayer in situ.
I might be needing more help, but I'm trying to get it working.

Steen

Title: Re: need help on reading each line from a file into a separate variable
Post by: Greg Erskine on May 23, 2014, 07:37:33 PM

Quote from: sbp on May 22, 2014, 01:31:18 PM

Quote from: Greg Erskine on May 21, 2014, 09:33:38 PM

Another temp file fudge using your input file format.

Code: [Select]

awk '{ print "var"NR"="$0 }' FILE.txt > temp.sh && . temp.sh
regards

Hi Greg

Thank you for your suggestion it is working fine. I need it for allowing update of piCorePlayer in situ.
I might be needing more help, but I'm trying to get it working.

Steen

Hi Steen,

Happy to help if I can. Ironically I only knew an answer because I have been going over your piCorePlayer scripts.

regards

Title: Re: need help on reading each line from a file into a separate variable
Post by: theYinYeti on May 30, 2014, 06:04:58 AM

If using bash, an array seems best to me:

Code: [Select]

while read line; do
  vars[${#vars[*]}]="$line"
done </path/to/file
Else use eval:

Code: [Select]

cpt=0
while read line; do
  cpt=`expr $cpt + 1`
  eval "var${cpt}=\"\$line\""
done </path/to/file