NAME

       retry - Repeat command until a criteria is met, usually success.

SYNOPSIS

       retry [-v] [-h] [-u until] [-w while] command ...

DESCRIPTION

       The  tool  repeats  the  given command until the command is successful, backing off with a
       configurable delay between each attempt.

       Retry captures stdin into memory as the data is passed to the repeated command,  and  this
       captured  stdin is then replayed should the command be repeated. This makes it possible to
       embed the retry tool into shell pipelines.

       Retry captures stdout into memory, and if the command was successful stdout is  passed  on
       to stdout as normal, while if the command was repeated stdout is passed to stderr instead.
       This ensures that output is passed to stdout once and once only.

OPTIONS

       -d seconds, --delay=seconds
              The number of seconds to back off after  each  attempt.  Multiple  comma  separated
              delays allow subsequent delays to be different, with the last delay repeated.

       -m message, --message=message
              A  message  to  include in the notification when repeat has backed off. Defaults to
              the command name.

       -t times, --times=times
              The number of times to retry the command. By default we try forever.

       -u criteria, --until=criteria
              Keep repeating the command until any one of the comma separated  criteria  is  met.
              Options  include  'success',  'true',  'fail',  ’false',  an  integer or a range of
              integers.  Default is 'success'.

       -w criteria, --while=criteria
              Keep repeating the command while any one of the comma separated  criteria  is  met.
              Options  include  'success',  'true',  'fail',  ’false',  an  integer or a range of
              integers.

       -h, --help
              Display this help message.

       -v, --version
              Display the version number.

RETURN VALUE

       The retry tool returns the return code from the command being executed, once the  criteria
       is reached.

       If  the  command  was interrupted with a signal, the return code is the signal number plus
       128.

       If the command could not be executed, or if the options  are  invalid,  the  status  1  is
       returned.

EXAMPLES

       In this basic example, we repeat the command forever.

               ~$ retry --until=success -- false
               retry: 'false' returned 1, backing off for 10 seconds and trying again...
               retry: 'false' returned 1, backing off for 10 seconds and trying again...
               retry: 'false' returned 1, backing off for 10 seconds and trying again...

   ^C
       In  this  more complex example, each invocation of curl is retried until curl succeeds, at
       which point stdout is passed once and once only to the next element in the pipeline.

               ~$ retry -- curl --fail http://localhost/entities | \
               jq ... | \
               retry -- curl --fail -X POST http://localhost/resource | \
               logger -t resource-init

       In this example, we stagger each delay exponentially  until  64  seconds,  which  is  then
       repeated until interrupted.

               ~$ retry --until=success --delay "1,2,4,8,16,32,64" -- false
               retry: false returned 1, backing off for 1 second and trying again...
               retry: false returned 1, backing off for 2 seconds and trying again...
               retry: false returned 1, backing off for 4 seconds and trying again...
               retry: false returned 1, backing off for 8 seconds and trying again...
               retry: false returned 1, backing off for 16 seconds and trying again...
               retry: false returned 1, backing off for 32 seconds and trying again...
               retry: false returned 1, backing off for 64 seconds and trying again...
               retry: false returned 1, backing off for 64 seconds and trying again...
               retry: false returned 1, backing off for 64 seconds and trying again...

   ^C

AUTHOR

       Graham Leggett <minfrin@sharp.fm>

                                           retry-1.0.5                                   retry(1)