script help

[sk8rrr]

hey guys, im making a practice script right now, so far it jsut demands the user for a filename.
how would i make it say an error msg on teh screen if the file does not exist, and how do i make it count the number of lines in teh file?

[i92guboj]

hey guys, im making a practice script right now, so far it jsut demands the user for a filename.
how would i make it say an error msg on teh screen if the file does not exist, and how do i make it count the number of lines in teh file?

To count lines, you can use "wc -l <filename>", if you want only the number, you can pipe it like "cat <filename> | wc -l".

To do something if a file doesn't exist, you can use this in bash:

if [ ! -f <filename> ]
then
<do something>
fi

Note however, that that check will also work if <filename> is a directory, a symlink, a socket, a device node or anything that is not strictly a regular file, which might or might not be convenient.

You can add more checks to see if that's the case and so the script would act consequently. Read the bash man page for additional info on that things, and ask here if you need more info.

[sk8rrr]

k so , so far i got
#!/bin/bash

echo -n "Please enter XHTML filename: "

read filename

if [ ! -f <filetest> ]
then
<correct>

else
<incorrect>
fi


-it asks for file name, when entered, it says error ,no matter on filename, and also says echo <correct>. how do i set the variable that only the file called "tester1" is teh corect one, and all others get teh error

[i92guboj]

I am not sure if I understand it correctly, but maybe what you want is something in the lines of

if [ "$filename" == "tester1" ]
then
<foo>
else
<bar>
fi

[sk8rrr]

thanks for attempt, i figured it out, possibly the easy way. works now to ask for file and show the number of lines.

is there a way to make it so, each time a filename that is not existant is entered there is a custom error message? or will it always be a standard message for error?

[Cabhan]

Yeah. How are you doing it now?

read filename

if [ -f "$filename" ]; then
    echo "Congrats, the file exists!"
else
    echo "The file $filename does not exist :'("
fi

[sk8rrr]

ye man thanks alot thats pretty clsoe to whwta im trying to get at.