The directory containing the shell script, 'hotbackup.sh', is not listed
in your PATH environment variable. Bash, like most other Unix shells
(sh, ksh, and csh for example) use the PATH environment variable to
find shell scripts and other programs for execution.
The PATH environment variable is a colon separated list of directory
names. You can see the current value of your PATH environment variable
with the command
echo $PATH. For example:
# echo $PATH
/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:
/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin
|
In Bash, you can add a directory to you PATH environment variable with the command
PATH=$PATH:/some/new/directory, replacing
/some/new/directory with
the absolute path name of the directory you want to add to your
PATH environment variable. For example, if I wanted to add the home directory of the username, wolfpack, I would do the following:
# PATH=$PATH:/home/wolfpack
# echo $PATH
/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:
/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin:/home/wolfpack
|
See the Bash man page (or the man page
for your specific Unix shell) for information on how
to set and change environment variables.
When Bash, and most other Unix shells, is given a command that does
not contain a slash, it will search each directory listed in the
PATH environment variable for a file with the same name as the command.
If it finds such a file, it will attempt to run it. If it does not
find such a file, Bash will give the error message
bash: hotbackup.sh: command not found.
If the command contains a slash, Unix shells will assume the command
is directly naming a file to be executed. If that file does not
exist, Bash will give the error
bash: /home/gavin/foo: No such file or directory. Using this you
can execute any shell script without having Bash search the PATH
environment variable. For example, if the shell script 'hotbackup.sh'
is in your current directory, you can simply use the command
'
./hotbackup.sh' to execute it. Otherwise you will have to provide the full path to the filename.
