Wastholm.com

The Fault-Tolerant Shell (ftsh) is a small language for system integration that makes failures a first class concept. Ftsh aims to combine the ease of scripting with very precise error semantics. It is especially useful in building distributed systems, where failures are common, making timeouts, retry, and alternation necessary techniques.

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If any element of the script fails, all running process trees are reliably cleaned up, and the block is tried again with an exponential backoff. You might think of this as exception handling for scripts.