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Accepted
moata_u
Asked: 2011-03-10 23:06:15 +0800 CST

Read file into array

  • 772

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
command-line

2 Answers

  1. Best Answer

    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.

    • 10 
  2. 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
    • 0