[SOLVED] CSH Permission Denied When Accessing Local File

wafflesausage · 03-09-2011, 08:49 PM

I've just recently started learning shell scripting and I've been working on a basic csh script, but I've been having a few problems. Here's the script

Code:

#!/bin/csh
echo Enter a file name
$< = FILE                                       ##Name of file
echo enter a size (in kilobytes) to monitor
SIZETOMON = $<                                  ##Size value that's input by user
du -k $FILE = $SIZE                             ##Size of the file that the user wishes to monitor
while (1)
if $SIZE > $SIZETOMON then
echo ALERT: File size is greater than $SIZETOMON
end

And here's the output

Code:

/home/lucer/foo.txt: Permission denied.
Badly placed ()'s.

I'm not really sure what the issue is with the "badly placed ()'s" or why it won't let me access files that I can access with the same shell when it's not in a script. Anyone have any ideas?

Edit:Fixed glaring punctuation error

corp769 · 03-09-2011, 09:15 PM

Try enclosing the echo statements in quotation marks:

Code:

#!/bin/csh
echo "Enter a file name"
$< = FILE
echo "enter a size (in kilobytes) to monitor"
SIZETOMON = $<
du -k $FILE = $SIZE
while (1)
if $SIZE > $SIZETOMON then
echo "ALERT: File size is greater than $SIZETOMON"
end

wafflesausage · 03-09-2011, 09:30 PM

Quote:

Originally Posted by corp769

Try enclosing the echo statements in quotation marks:

Code:

#!/bin/csh
echo "Enter a file name"
$< = FILE
echo "enter a size (in kilobytes) to monitor"
SIZETOMON = $<
du -k $FILE = $SIZE
while (1)
if $SIZE > $SIZETOMON then
echo "ALERT: File size is greater than $SIZETOMON"
end

I just solved the parentheses error by removing the parentheses around "in kilobytes". It seemed to be superficial, and I could probably find a way to esape it, but that's not my actual concern. The permission error is still there.

corp769 · 03-09-2011, 10:02 PM

Are you running the script as your normal user? And is the foo.txt already there? If so, what are the permissions of the file?

wafflesausage · 03-09-2011, 10:10 PM

Quote:

Originally Posted by corp769

Are you running the script as your normal user? And is the foo.txt already there? If so, what are the permissions of the file?

Yes, I tried it before with sudo and it didn't work. I just now I tried it with the permissions of 770 and it worked without root privileges, but now it says

Code:

Enter a file name
/home/lucer/foo.txt
/home/lucer/foo.txt: 1: SDFDFA: not found
enter a size in kilobytes to monitor
89
89: Command not found.
FILE: Undefined variable.

"SDFDFA" is the contents of the file, but I need $FILE to be the input from stdin.

corp769 · 03-09-2011, 10:23 PM

I think you need to have it like so:

Code:

set file = $<

wafflesausage · 03-09-2011, 11:08 PM

Quote:

Originally Posted by corp769

I think you need to have it like so:

Code:

set file = $<

Yes, thanks a lot. Now all I have to do is find a way to chop off the non-numerical data from du and get around the "variable must begin with number" error.

corp769 · 03-09-2011, 11:42 PM

What do you mean? Show me your code so far.

wafflesausage · 03-10-2011, 12:27 AM

Quote:

Originally Posted by corp769

What do you mean? Show me your code so far.

Code:

#!/bin/csh
echo Enter a file name
set file aFILE = $<                                             ##Name of file
echo enter a size in kilobytes to monitor
set SIZE = $<                                                   ##Size value that's input by user
set SIZETOMON = du -k $aFILE | sed s/$aFILE//g                  ##Size of the file that the user wishes to monitor
while (1)
if $SIZE > $SIZETOMON then
echo ALERT: File size is greater than $SIZETOMON
end

If you want to run it for yourself, you can't specify a full path because of the way I set it set up to sed out the non-numerical characters from the output of du. I'll probably just find a workaround to that myself if it becomes to much of an inconvenience.

corp769 · 03-10-2011, 12:36 AM

Show me the output of "du -k $aFILE" and "du -k $aFILE | sed s/$aFILE//g" if you could so I can see what you are talking about. I would rather see the output on your end. Of course replace aFILE with the actual file and so forth...

wafflesausage · 03-10-2011, 12:22 PM

Quote:

Originally Posted by corp769

Show me the output of "du -k $aFILE" and "du -k $aFILE | sed s/$aFILE//g" if you could so I can see what you are talking about. I would rather see the output on your end. Of course replace aFILE with the actual file and so forth...

Actually, I switched that line so it now reads

Code:

du -k $aFILE | awk '{print $1}'

which prints only the size of the specified file in kilobytes (without the name as it did before). I still get the error that states

Code:

set: Variable name must begin with a letter.
SIZETOMON: Undefined variable.

It was my understanding that in shell scripting that one doesn't have to specify whether a variable is a string, float, integer, etc., but that doesn't seem to be the case here. And just to clarify, aFILE is a variable that is specified by the user which the script "asks for" on line 3.

corp769 · 03-10-2011, 12:28 PM

Code:

set SIZETOMON = `du -k $aFILE | sed s/$aFILE//g`

Just noticed this - Try using backticks. Backticks will execute whatever is inside of them.

corp769 · 03-10-2011, 12:30 PM

And I have a question about the following:

Code:

set file aFILE = $<

Shouldn't be this?

Code:

set aFILE = $<

wafflesausage · 03-10-2011, 12:39 PM

Quote:

Originally Posted by corp769

Code:

set SIZETOMON = `du -k $aFILE | sed s/$aFILE//g`

Just noticed this - Try using backticks. Backticks will execute whatever is inside of them.

I tried it with the backticks, but it still says

Code:

SIZETOMON: Undefined variable

Without the backticks, it says

Code:

set: Variable must begin with a letter
SIZETOMON: Undefined variable.

Really, what I'm trying to do here is have the SIZETOMON variable have the numerical value of the output of

Code:

du -k $aFILE | awk '{print $1}'

and compare it against SIZE, which is a value input by the user.

corp769 · 03-10-2011, 12:42 PM

Can you do what I asked before about running the "du -k $aFILE | sed s/$aFILE//g" by itself on the command line and substituting the appropriate filename?