linux scripting help needed read from file line by line exc commands each line read

atokad · 12-25-2003, 07:24 PM

I need a script however probably pretty simple preferably bash

synopsis

file reads

a
b
c
d

I need a script to read the file line by line at each line useing the content of that line as a variable to be used in a command.example

script reads line 1 sees the a then uses the a as a variable in a command

then reads the next line and repeats itself

hope that explains it easy enough

help is much appreciated

thank you

atokad

fr0zen · 12-25-2003, 09:46 PM

First you want to read in the data from the file. This can be accomplished in several ways, the easiest is

Code:

FILE=`cat filename`

Then, you want to echo this file data out, and look at each line. For each line, simply execute the line as though it were a command:

Code:

echo "$FILE" | \     # notice we PIPE the output data to the next line (denoted by \)
while read CMD; do   # CMD is the line, this could be any variable name
   $CMD             # just execute it
done

atokad · 12-26-2003, 09:24 AM

well i figured out that my script i was useing was working however not correctly

this is the script

if [ -f /file ]; then
while read FILE; do
command $FILE
done < /file
fi

it works but if i place these lines in the file

1
2
3
4
5
6
7
8

it will read and work all the way to the last line the loop exits before
it read 8.

any ideas on why this happens

atokad

cfaj · 12-26-2003, 08:22 PM

Do you have a linefeed after the last line?

atokad · 12-26-2003, 10:24 PM

what are your referring to as a line feed
the

< /file

reads the file into the while command

elaborate i am firewall guru but not really a great scriptor

atokad