hal_signal_new(3hal)

💖 hal_signal_new — bestie, let's talk HAL signals 💖

okay so this is from the HAL manual, section 3hal, and it's about four little functions that let you make and break connections between pins and signals. it's giving matchmaker energy fr fr 🌸

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✨ SYNTAX ✨

int hal_signal_new(const char *signal_name, hal_type_t type)

int hal_signal_delete(const char *signal_name)

int hal_link(const char *pin_name, const char *signal_name)

int hal_unlink(const char *pin_name)

like. four whole functions. they said "we contain multitudes" 💅

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🎀 ARGUMENTS 🎀

• signal_name — the name of the signal. that's it, that's the whole vibe 🦋
• pin_name — the name of the pin. iconic, no notes 👑
• type — the type of the signal, exactly as it's laid out over in hal_type_t(3hal). go check that one, bestie 📚

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🌈 DESCRIPTION 🌈

okay so hal_signal_new creates a brand new signal object. main character behavior, honestly. once a signal exists, pins can get linked to it with hal_link. here's the tea tho: the signal object is the one that holds the actual storage for the signal data — the pins linked to it just have pointers that point at that data. so the signal is carrying everything, and the pins are just. pointing. respectfully 🫶

'name' is the name of your new signal, and it can be no longer than HAL_NAME_LEN characters. and if there's already a signal with that same name? the call will fail. no duplicates allowed, this is not a group chat with three people named "alex" 💀

hal_link links a pin to a signal. now here's the fine print:

• if the pin is already linked to the signal you're asking for — congrats, the command succeeds. nothing to do, we love a no-op 🎉
• if the pin is already linked to some other signal — that's an error. sorry babe.
• in either case, the existing connection is not modified. so no sneaky rewiring happens behind your back.
• wanna break an existing connection? use 'hal_unlink', that's literally what she's for 💅
• and if the signal already has other pins linked to it? they're unaffected. one signal can be linked to many pins, but a pin can be linked to only one signal. it's giving polyamorous signal, monogamous pin 🦋✨

hal_unlink unlinks any signal from the specified pin. done and dusted, periodt.

hal_signal_delete deletes a signal object. and any pins linked to that object get unlinked. she takes the whole situationship down with her 😭

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⭐ RETURN VALUE ⭐

returns a HAL status code. that's the whole answer, no elaboration, iykyk.

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👀 SEE ALSO 👀

• hal_type_t(3hal)

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real talk bestie: signals are shared storage, pins are pointers to it. one signal → many pins. one pin → exactly one signal. internalize that and you're set 💜

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mwah, that's the whole page 🌸 this was LinuxCNC Documentation, dated 2006-10-12, and the page is hal_signal_new(3hal) — go forth and link responsibly, queen 👑💖