Hello,

I am having an issue changing ownership using bash with variables.

I am testing with Yad and everything works but cant get the bash scripting to chown $frmChgOwn

Currently running as root have tried normal user and sudo still gives same result.

How it works: the Path is absolute I am testing using /usr/
Creating a directory name of: MyDir
Assigning a Group Call Teachers
And changing Ownership to Students

Here is the script:

#!/bin/bash
#Create Application Dynamics - Frame Window and fields
frmdata=$(yad --title "Create Directory" --form --width 300 --height 300 \
--field="Path" \
--field="Directory Name" \
--field="Group Owner" \
--field="Change Owner" \
--directory \
)

#Capture and parse user INPUT from fields
frmPath=$(echo $frmdata | awk 'BEGIN {FS="|"}{ print $1}')
frmDirName=$(echo $frmdata | awk 'BEGIN {FS="|"}{ print $2}')
frmGroup=$(echo $frmdata | awk 'BEGIN {FS="|"}{ print $3}') #If left blank default will be root
frmChgOwn=$(echo $frmdata | awk 'BEGIN {FS="|"}{ print $4}') #If left blank default will be root

#Execute command with user input as a variable
mkdir -p $frmPath$frmDirName

#Logic to check for empty variable in the Group Field and error control
# -z = if variable is empty
# -n = If variable is not empty
#
if [ -z "$frmGroup" ]; then
echo "Group Empty"
elif [ -n "$frmGroup" ]; then
chgrp $frmGroup $frmPath$frmDirName
elif [ -z "$frmChgOwn" ]; then
echo "Change Owner Empty"
elif [ -n "$frmChgOwn" ]; then
chown $frmChgOwn $frmPath$frmDirName
exit 0
fi

I admit: I am too lazy to copy and execute your script. But insert this statement before the line:
and see exactly what command is executed by chown. Either the command is not executed, or is executed with parameters you did not expect.

jlinkels

Shouldn't frmGroup and frmChgOwn be checked independently, in separate if-then-else clauses?

Thank You

Here is the new logic and works well


#Logic to check for empty variable in the Group and Owner Field and error control
# -z = if variable is empty
# -n = If variable is not empty
#
set -x
if [ -z "$frmGroup" ]; then
echo "Group Empty"
exit 1
elif [ -n "$frmGroup" ]; then
chgrp $frmGroup $frmPath$frmDirName
fi

if [ -z "$frmChgOwn" ]; then
echo "Change Owner Empty"
exit 1
elif [ -n "$frmChgOwn" ]; then
chown $frmChgOwn $frmPath$frmDirName
fi

Actually the error was spotted by MadeInGermany. Somehow I am not very well able to spot errors in code unless I put a serious amount of time in. But once I see the trace of execution errors pop out. That is why I know the -x option so well.

jlinkels

While it works correctly now, there is no point in having an elif with the opposite of the if condition.
A simple else means the opposite of the if condition.
And if you have an exit in the if branch you do not even need an else...

and also there is no reason to use even else if there was a then .. exit 1