echo command error "file exits"

muby · 03-17-2010, 05:49 AM

Hi Everyone,

I faced a issue with updating a file contents with echo command which fails with error as below:

echo "foo" > bar //to create a file named "bar"
echo "foobar" > bar //to edit its contents

The latter fails, it prompts "File exists"

i.e.

~>echo "foo" > bar
~>echo "foobar" > bar
bar: File exists.
~>cat bar
foo
~>

anybody had similar issue or know how to fix this?
Thanks

Sayan Acharjee · 03-17-2010, 05:51 AM

Quote:

Originally Posted by muby

Hi Everyone,

I faced a issue with updating a file contents with echo command which fails with error as below:

echo "foo" > bar //to create a file named "bar"
echo "foobar" > bar //to edit its contents

The latter fails, it prompts "File exists"

i.e.

~>echo "foo" > bar
~>echo "foobar" > bar
bar: File exists.
~>cat bar
foo
~>

anybody had similar issue or know how to fix this?
Thanks

Try this:
echo "foobar" >> bar

vinaytp · 03-17-2010, 05:57 AM

Check the output of

Code:

echo $-
himBCH

If you find the C in the output, it indicates it won't allow existing file to overwirte.

You may turn it off using

Code:

set -o noclobber off

After creating file

Quote:

echo "foo" > bar //to create a file named "bar"

You will not be able to perform below operation, if noclobber option is set to ON. I guess this is your problem.

Code:

echo "foobar" > bar

To edit the file. Personally, It is better if you open the file using Vi and edit.

muby · 03-17-2010, 07:08 AM

Thanks vinaytp & sayan_acharjee for your replies,

when i run the command, i get this error

Code:

~>echo $-
Illegal variable name.

is it dependent on which shell i use? I'm using tcsh

Edit: regardless, this was solved with

Quote:

set -o noclobber off

Thanks a lot

vinaytp · 03-17-2010, 07:34 AM

I have not used tcsh. Yes I checked with tcsh, it will not support $- variable.

You have to check shell properties to find alternative for $-