How can I read file in shell script , then assign each line to an variable that i can use later ,,,(am thinking in way to load an default setting from file)

i already try :

process (){
}
FILE=''
read -p "Please enter name of default file : " FILE
if [ ! -f $FILE ]; then echo "$FILE : does not exists " exit 1
elif [ ! -r $FILE ]; then echo "$FILE : can not read "
fi
exec 0<"$FILE"
n=0
while read -r line
do (assign each line to an variable)
done

2

2 Answers

For configuration purposes it's probably easiest to define the parameters in the configuration file in bash syntax and later source it using . /path/to/config.

Example default.cfg:

parameter_a=100
parameter_b=200
parameter_c="Hello world"

Example script.sh:

#!/bin/bash
# source the default configuration
. /path/to/default.cfg
echo $parameter_a
echo $parameter_b
echo "$parameter_c"
...

---

If you don't like that approach you can also read the lines into an array:

while read line
do array+=("$line")
done < some_file

To access the items you would then use ${array[index]}, e.g.:

for ((i=0; i < ${#array[*]}; i++))
do echo "${array[i]}"
done

(Where ${#array[*]} is the size of the array.)

Read more about arrays in bash here.

4

c=0 # counter
# read whole file in loop
while read line
do textArray[$c]=$line # store line c=$(expr $c + 1) # increase counter by 1
done < $FILE
# get length of array
len=$(expr $c - 1 )
# use for loop to reverse the array
for (( i=$len; i>=0; i-- ));
do echo ${textArray[$i]}
done

1

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