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Functions

Perform a branching conditional

Terminal - Perform a branching conditional
true && { echo success;} || { echo failed; }
2009-04-02 01:49:25
Functions: echo true
23
Perform a branching conditional

This will perform one of two blocks of code, depending on the condition of the first. Essentially is a bash terniary operator.

To tell if a machine is up:

ping -c1 machine { echo succes;} || { echo failed; }

Because of the bash { } block operators, you can have multiple commands

ping -c1 machine && { echo success;log-timestamp.sh }|| { echo failed; email-admin.sh; }

Tips:

Remember, the { } operators are treated by bash as a reserved word: as such, they need a space on either side.

If you have a command that can fail at the end of the true block, consider ending said block with 'false' to prevent accidental execution

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
[[ test_condition ]] && if_true_do_this || otherwise_do_that
2009-02-20 21:45:21
User: stallmer
24

instead of writing:

if [[ "$1" == "$2" ]]; then

echo "$1 is equal $2"

else

echo "$1 differs from $2"

fi

do write:

[[ "$1" == "$2" ]] && echo "$1 is equal $2" || echo "$1 differs from $2"

Know a better way?

If you can do better, submit your command here.

What others think

and what about this case?

true && { false; } || { echo failed; }

try it :D

Comment by acirulli 281 weeks ago

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