Using the first column of a file as input in a script - bash

Question

I am having some problems with using the first column ${1} as input to a script.
Currently the portions of the script looks like this.
#!/bin/bash
INPUT="${1}"
for NAME in `cat ${INPUT}`
do
SIZE="`du -sm /FAServer/na3250-a/homes/${NAME} | sed 's|/FAServer/na3250-a/homes/||'`"
DATESTAMP=`ls -ld /FAServer/na3250-a/homes/${NAME} | awk '{print $6}'`
echo "${SIZE} ${DATESTAMP}"
done
However, I want to modify the INPUT="${1}" to take the first {1} within a specific file. This is so I can run the lines above in another script and use a file that is previously generated as the input. Also to have the output go out to a new file.
So something like:
INPUT="$location/DisabledActiveHome ${1}" ???
Here's my full script below.
#!/bin/bash
# This script will search through Disabled Users OU and compare that list of
# names against the current active Home directories. This is to find out
# how much space those Home directories take up and which need to be removed.
# MUST BE RUN AS SUDO!
# Setting variables for _adm and storage path.
echo "Please provide your _adm account name:"
read _adm
echo "Please state where you want the files to be generated: (absolute path)"
read location
# String of commands to lookup information using ldapsearch
ldapsearch -x -LLL -h "REDACTED" -D $_adm#"REDACTED" -W -b "OU=Accounts,OU=Disabled_Objects,DC="XX",DC="XX",DC="XX"" "cn=*" | grep 'sAMAccountName'| egrep -v '_adm$' | cut -d' ' -f2 > $location/DisabledHome
# Get a list of all the active Home directories
ls /FAServer/na3250-a/homes > $location/ActiveHome
# Compare the Disabled accounts against Active Home directories
grep -o -f $location/DisabledHome $location/ActiveHome > $location/DisabledActiveHome
# Now get the size and datestamp for the disabled folders
INPUT="${1}"
for NAME in `cat ${INPUT}`
do
SIZE="`du -sm /FAServer/na3250-a/homes/${NAME} | sed 's|/FAServer/na3250-a/homes/||'`"
DATESTAMP=`ls -ld /FAServer/na3250-a/homes/${NAME} | awk '{print $6}'`
echo "${SIZE} ${DATESTAMP}"
done
I'm new to all of this so any help is welcome. I will be happy to clarify any and all questions you might have.
EDIT: A little more explanation because I'm terrible at these things.
The lines of code below came from a previous script are a FOR loop:
INPUT="${1}"
for NAME in `cat ${INPUT}`
do
SIZE="`du -sm /FAServer/na3250-a/homes/${NAME} | sed 's|/FAServer/na3250-a/homes/||'`"
DATESTAMP=`ls -ld /FAServer/na3250-a/homes/${NAME} | awk '{print $6}'`
echo "${SIZE} ${DATESTAMP}"
done
It is executed by typing:
./Script ./file
The FILE that is being referenced has one column of user names and no other data:
User1
User2
User3
etc.
The Script would take the file and look at the first users name, which is reference by
INPUT=${1}
then run a DU command on that user and find out what the size of their HOME drive is. That would be reported by the SIZE variable. It will do the same thing with the DATESTAMP in regards to when the HOME drive was created for the user. When it is done doing the tasks for that user, it would move on to the next one in the column until it is done.
So following that logic, I want to automate the entire process. Instead of doing this in two steps, I would like to make this all a one step process.
The first process would be to generate the $location/DisabledActiveHome file, which would have all of the disabled users names. Then to run the last portion to get the Size and creation date of each HOME drive for all the users in the DisabledActiveHome file.
So to do that, I need to modify the
INPUT=${1}
line to reflect the previously generated file.
$location/DisabledActiveHome

Answer 1

I don't understand your question really, but I think you want this. Say your file is called file.txt and looks like this:
1 99
2 98
3 97
4 96
You can get the first column like this:
awk '{print $1}' file.txt
1
2
3
4
If you want to use that in your script, do this
while read NAME; do
echo $NAME
done < <(awk '{print $1}' file.txt)
1
2
3
4
Or you may prefer cut like this:
while read NAME; do
echo $NAME
done < <(cut -d" " -f1 file.txt)
1
2
3
4
Or this may suit even better
while read NAME OtherUnwantedJunk; do
echo $NAME
done < file.txt
1
2
3
4
This last, and probably best, solution above uses IFS, which is bash's Input Field Separator, so if your file looked like this
1:99
2:98
3:97
4:96
you would do this
while IFS=":" read NAME OtherUnwantedJunk; do
echo $NAME
done < file.txt
1
2
3
4

Answer 2

INPUT="$location/DisabledActiveHome" worked like a charm. I was confused about the syntax and the proper usage and output