chmod command is not working in shell script

Question

I am writing a script that needs to create a file if an argument is passed to he script. If no argument is passed then it will ask for fileName but it needs to have default permission as -rwx- --- - ---. I am using this command chmod a=-rwx to remove all the default permissions and then i am using chmod u=+rwx to get the desired permission as stated but it is not working. Can anyone help please?

#!bin\bash

if [ $#==0 ]; then
    echo "Please enter a file name?"
    read fileName
    if [ -f $fileName ]; then
        echo "File already exist! Opening for Editing"
        sleep 3
        nano $fileName
    else
        echo "File created with the name $fileName"
        echo "Opening $fileName for editing "
        sleep 3
        echo "#!bin\bash" >$fileName
        nano $fileName
    fi
elif [ -f $1 ]; then
    echo "File already exists with the name $1"
    echo "Opening for editing"
    sleep 3
    nano $1
else
    fileName="$1"
    chmod a=-rwx $fileName
    chmod u=+rwx $fileName
    echo "File created with the name $filename"
    echo "Opening $fileName for editing "
    echo "#!bin\bash" >$fileName
    sleep 3
    nano $1

fi

Answer 1

Your chmod syntax is incorrect. The operation is either = to set the mode to a specific value, + to add modes, or - to remove modes; you can't combine them with =+ and =-.

You can perform multiple operations on a single file by separating them with ,.

So it should be:

chmod go-rwx,u+rwx "$fileName"

Another problem:

if [ $#==0 ]

should be

if [ $# -eq 0 ]

Use -eq for numeric comparisons, and spaces are needed around operators in shell conditions.

Third problem: You're doing the chmod before you create the file. Put it after

echo "#!/bin/bash" >"$fileName"

Fourth problem: #!bin\bash should be #!/bin/bash.

Finally, remember to quote your variables, in case they contain spaces.

Answer 2

Add the actual path of chmod: Ex: which chmod

/usr/bin/chmod

In your script add the complete path of chmod and try it out.