Shell Programming and Scripting

Hi,
i have a file (filename xyz.file) and i scp it daily to server B. B runs a job daily and remove it. A sends it at 9am, B removes it at 915am.

Now i have another server C, it also scp a file (xyz.file) to B. C will send to B at 930am and B will remove it at 10am.

My worry is if B fails to remove it at 915am, and when i scp from C at 930, it will overwrite the existing file.

(1) is there any way to scp without over writing?
(2) is there any command that i can use to check if the file still exists after 915 in B( the file sent from A) , i will not send the file at 930 from C.

It is not advisable to use another filename for the second scp due to business rules.
please advise.

If you can use rsh then how about running (from A):

Code:

command
status=$(rsh B "ls -l /somedirectory/xyz.file" 2>/dev/null | wc -l)

$status will have value of 0 is file doesn't exist or 1 if it does

thanks for the suggestion, i'll try that out.

It worked! thank you very much.

Hi,

Because i am executing the command in a perl script, i will be using the following line

Code:

system (rsh B "ls -l /somedirectory/xyz.file" 2>/dev/null | wc -l);

how can i get it to return the value to a variable in perl so that i can test the value of the variable?

Instead of using system, use the ` (backticks) just like you do in a shell script.

Code:

$output=`rsh B "ls -l /somedirectory/xyz.file" 2>/dev/null | wc -l`;

Hi all,

i realise option (2) was not feasible because it would cause a backlog if i cannot scp due to the existance of the unprocessed file.

how can i get the file over and append it into the unprocessed file?

I've tried to use this, will it prevent over writting?

Code:

system (/local/bin/ssh $host cat < $local \">>\" $Target")

i've also encoutered an error "/local/bin/ssh: No such file or directory". I think its the directory ( in italics) that is causing the error, how can i find out the correct directory of my machine?

# which ssh