Re: Pausing a bash script

[Paul Jarc]

DanSandbergUCONN <Daniel.Sandberg@uconn.edu> wrote:
> Hi All - If I want to write a script that uses ftp to transfer a file and
> then, only after the file has been successfully transferred, I do something
> else - how do I tell my script to wait until the ftp is finished before
> doing the next command? Is that even possible?

Waiting for the command to finish is what the shell normally does.  If
a command is followed by "&", then you get the other behavior - the
command is started, and then the shell immediately continues with the
next command.  Without "&", the shell waits for the command to finish
before proceeding.

To test that the command was successful, there are a few different
choices.  You could use "set -e", as long as your script uses simple
enough syntax.  But there are enough tricky situations that get in the
way of "set -e" that I never use it.  You could put "&&" after every
command, to ensure that the script will stop at the first command that
fails.  That's what I generally do.  Or, if the ftp command is the
only one whose success you care about, you could use "if":
...
if ftp_command; then
  echo the transfer was successful
  else exit
fi
...


paul