BASH script with goto or if statements?

tarken · 09-24-2018, 12:19 PM

Hello all!

I am writing a script that will umount/mount certain batches of mounts within fstab. I am trying to have it all within one script with a little sub menu but I am having some questions about that.

The general syntax should be something like:

What would you like to remount?

1. Windows Shares
2. Linux NFS Shares
3. Printer folders

Based upon what they select, will run different commands. I was thinking there was a goto command, but I can't seem to find one. Would I just nest them in if statements? If the number is 1 do this else do nothing. If 2 do this, else do nothing. If 3 do this, else do nothing.

I was also going to use the mailx command to email me whenever someone runs this command.

Any tips?

teckk · 09-24-2018, 01:25 PM

Quote:

If the number is 1 do this else do nothing. If 2 do this, else do nothing. If 3 do this, else do nothing.

Quick examples:

Code:

read -p "Enter 1 2 or 3 :" num
if [ "$num" -eq "1" ]; then
    echo "You entered 1"
elif [ "$num" -eq 2 ]; then
    echo "You entered 2"
elif [ "$num" -eq 3 ]; then
    echo "You entered 3"
else echo "You entered a number out of range"
fi

Code:

options="Quit WindowsShares LinuxNFSShares Printerfolders"
select opt in $options; do
    case $opt in
        Quit) clear; exit;;
    
        WindowsShares) echo "Windows Shares" ;;
        
        LinuxNFSShares) echo "Linux NFS Shares" ;;
        
        Printerfolders) echo "Printer folders" ;;
    esac
done

tarken · 09-24-2018, 02:35 PM

How do I use that bottom part?

This is what I have right now"

Code:

echo "What would you like to do?"
echo "1. Re mount Windows shares"
echo "2. Re mount NFS shares"
echo "3. Re mount all shares"


read -p "Enter 1, 2, or 3:" num
if [ "$num" -eq "1" ]; then
    echo "You entered 1"
elif [ "$num" -eq 2 ]; then
    echo "You entered 2"
elif [ "$num" -eq 3 ]; then
    echo "You entered 3"
else echo "You entered a number out of range"
fi

##########################################################
# Forcibly unmount all CIFS/Windows shares in /etc/fstab #
##########################################################

echo "Trying to unmount all CIFS/Windows shares"

umount -t cifs


#########################################################
# Remount all CIFS/Windows shares in /etc/fstab #########
#########################################################

echo "Trying to mount all CIFS/Windows shares in /etc/fstab"

mount -a -t cifs


#####################################################
# Forcibly unmount all mount points in /etc/fstab ###
#####################################################

echo "Trying to forcibly unmount all mount points in /etc/fstab, please wait"

umount -a -f

#####################################################
# Remount all shares listed in /etc/fstab ###########
#####################################################

echo "Trying to mount all mount points in /etc/fstab, this should only take a few seconds"

mount -a

echo "If you did not get any errors, you are good to go. If you did get errors, please note them and let the team know"

How do I have it run only the part for which they select?

teckk · 09-24-2018, 05:07 PM

Those were examples on how to select an option. You'll going need to study bash a little.
http://mywiki.wooledge.org/BashFAQ
http://www.google.com/search?ie=ISO-...eference&gbv=1

Haven't checked any of those mount commands, looking at your script...

Here is a template using case, you'll have to write your script to do what you want done.

Code:

#! /usr/bin/env bash

clear

# PS3 prompt message
PS3="Select an option.:  "

#Make an array with options, quote spaced items.
options=(Quit "Mount Windows Shares" "Unmount Windows Shares" 
            "Mount NFS Shares" "Unmount NFS Shares")
            
#Make a selection menu for array
select opt in "${options[@]}"; do
    #case statements
    case $opt in
        Quit) clear
                exit
        ;;
    
        "Mount Windows Shares") echo "Mounting Windows Shares" 
                            #<1st comand here>
                            #<2nd command here>
        ;;
        
        "Unmount Windows Shares") echo "Unmounting Windows Shares" 
                            #<commands here>
                            #<commands here>
        ;;
                        
        "Mount NFS Shares") echo "Mounting NFS Shares"  
                            #<commands here>
        ;;
        
        "Unmount NFS Shares") echo "Unmounting NFS Shares"
                            #<commands here>
        ;;
    esac
done

You can also use if, then, else, elif in numerous ways.

Code:

echo "What fruit do you like best?"
read -p "apple, pear, or other? " answer

if test "$answer" = "apple"; then
    echo "Apple is a good fruit."
elif test "$answer" = "pear"; then
    echo "Pear is a sweet fruit"
else
    echo "Other fruit is good too."
fi

Code:

echo "What fruit do you like best?"
OPTIONS="apple pear other quit"

select opt in $OPTIONS; do
    if [ "$opt" = "apple" ]; then
        echo "Apple is a good fruit."
    elif [ "$opt" = "pear" ]; then
        echo "Pear is a sweet fruit."
    elif [ "$opt" = "other" ]; then
        echo "Other fruit is good too."
    elif [ "$opt" = "quit" ]; then
        exit
    fi
done

You can also echo your commands first to see what the output would be

Code:

echo "mount -t cifs ......"

See:
man mount
man echo
read -h