KVALID_STRING(3)

✨ KVALID_STRING(3) ✨ — the validation girlies of libkcgi

okay so bestie, listen 💖 this is the manual page for KVALID_STRING(3) from the library libkcgi, and it's literally the whole roster of predefined validation functions. they're small, they're iconic, they do one job each, and they ate. let's get into it 🎀

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🌸 SYNOPSIS 🌸

like all good things, it starts with some includes:

#include <sys/types.h>
#include <stdarg.h>
#include <stdint.h>
#include <kcgi.h>

int
kvalid_bit(struct kpair *kp);

int
kvalid_date(struct kpair *kp);

int
kvalid_double(struct kpair *kp);

int
kvalid_email(struct kpair *kp);

int
kvalid_int(struct kpair *kp);

int
kvalid_string(struct kpair *kp);

int
kvalid_stringne(struct kpair *kp);

int
kvalid_udouble(struct kpair *kp);

int
kvalid_uint(struct kpair *kp);

nine functions. same signature. no cap, they're all just int f(struct kpair *kp). simple queen behavior 👑

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🦋 DESCRIPTION 🦋

so the predefined kcgi(3) validation functions do their whole thing by checking kp->val and kp->valsz. when validation succeeds — slay — they set the appropriate kp->parsed field to the validated value and stash its type in kp->type. 💅

these functions were literally designed to go in the valid field of struct kvalid, which is documented over in khttp_parse(3). iykyk.

here's what each one actually validates:

• kvalid_bit() — a bit number, range 1 to 64 (like, first bit, second bit, and so on), or 0 to mean no bit at all. sets KPAIR_INTEGER. 🧚
• kvalid_date() — takes an ISO 8601 YYYY-MM-DD date and converts it to the number of seconds since or before the UNIX Epoch, 1970-01-01. dates before 1582 are not accepted, periodt. and it's not just syntax checking — it verifies the date's actually correct (days in month, leap years, etc.) because she's thorough like that. sets KPAIR_INTEGER. ⭐
• kvalid_double() — a signed double-precision floating-point number in strtod(3) format. sets KPAIR_DOUBLE. 🌈
• kvalid_email() — a loosely-validated e-mail address, at most 254 characters, with a user part (at least one character) and a domain part (at least one character). heads up bestie: this will allow many invalid e-mail addresses, but it will not prevent any otherwise valid ones by over-strict testing — it's giving lenient on purpose. the validated string gets trimmed for white-space and lowercased. sets KPAIR_STRING. 💌
• kvalid_int() — a 64-bit signed integer. sets KPAIR_INTEGER. 🔥
• kvalid_string() — a NUL-terminated string that's allowed to be empty. validation fails if kp->valsz does not match strlen(kp->val). sets KPAIR_STRING. 🍓
• kvalid_stringne() — the same as kvalid_string() except validation fails if the string is empty. the "ne" is basically "not empty", main character energy. 💀
• kvalid_udouble() — the same as kvalid_double() except validation fails if the number is zero or negative. 🙈
• kvalid_uint() — the same as kvalid_int() except validation fails if the number is negative. and heads up: the range does not extend to UINT64_MAX, it's limited to INT64_MAX. noted bestie 🫶

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👑 RETURN VALUES 👑

all the validation functions return 1 if validation succeeds or 0 if it fails. that's it. that's the whole vibe check. 💯

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🔍 SEE ALSO 🔍

kcgi(3), khttp_fcgi_init(3), khttp_parse(3), kutil_invalidate(3)

go read those next, they're all linked in the group chat ✨

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💜 AUTHORS 💜

these functions were written by Kristaps Dzonsons <kristaps@bsd.lv>. thank you legend 🫡

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💀 BUGS 💀

real talk: kvalid_double() and kvalid_udouble() might attempt to access locale information, which might fail in a sandbox. so if you're sandboxed and those two act up, that's why 😭 not their fault (kind of their fault).

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and that's the page!! this version came from the Debian packaging, dated $Mdocdate$, and yeah — it's still KVALID_STRING(3) at the end of the day 💖 bye bestie, go validate something 🌸