[ Thanks to Brandon for this link.
]
“What if you wanted to run a command and when it
finished, run another? Linux provides three ways to do this with a
slightly different end result. The semicolon (;), ampersand (&)
and the verticle pipe (|) all help the user “chain” commands
together.“[user@localhost ~]$ apt-get update ; apt-get upgrade
“In this example we are using the semicolon (;) to separate
these two commands. Using a semicolon tells the shell, “once the
first command finishes, run the second one”. Once apt-get update
finishes, the system will then run it again using the upgrade
option.“[user@localhost ~/project1]$ ./configure && make
&& make install“This command is mainly used by developers, software package
maintainers and Linux power users. This chain of commands compiles
a program and installs it. What the double-ampersands are telling
the system is “wait for the first command to successfully complete.
If it does complete successfully, run the next command”.