4
votes
4answers
1k views

Make cp return an error value if the target exists

Is there a way to make cp (from GNU coreutils on Linux) return a nonzero value in case the target file does already exist? Or is there any other small utility which is commonly available and which ...
26
votes
9answers
11k views

Correct locking in shell scripts?

Sometimes you have to make sure that only one instance of a shell script is running at the same time. For example a cron job which is executed via crond that does not provide locking on its own (e.g. ...
5
votes
3answers
3k views

Storing output of command in shell variable

I have an operation using cut that I would like to assign result to a variable var4=echo ztemp.xml |cut -f1 -d '.' I get the error: ztemp.xml is not a command The value of var4 never gets ...