and - conditionally execute a command
and is used to execute a command if the previous command was successful
(returned a status of 0).
and statements may be used as part of the condition in an
while or if block.
and does not change the current exit status itself, but the
command it runs most likely will. The exit status of the last foreground
command to exit can always be accessed using the $status variable.
The following code runs the make command to build a program. If the build
succeeds, make's exit status is 0, and the program is installed. If
either step fails, the exit status is 1, and make clean is run, which
removes the files created by the build process.
make; and make install; or make clean
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