ctype.h(3)

🌸 ctype.h — bestie edition 💅

okay so. this is <ctype.h> from avr-libc (that's the manual, section 3, and yes we're doing this together, hold my iced coffee 🧋).

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✨ NAME ✨

ctype.h — the header that's literally just out here classifying your characters and converting them, no cap 👑

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✨ SYNOPSIS ✨

💖 Functions 💖

🎀 Character classification routines 🎀

okay so these functions do character classification, periodt. they hand you back a true-or-false status depending on whether the character you passed in falls into that function's classification — like, isdigit() returns true if its argument is any value '0' through '9', inclusive. that's it, that's the whole vibe.

🚨 important bestie: if the input is not an unsigned char value, then all of these functions return false. not "maybe", not "undefined", just false. remember that. 🫶

int isalnum (int __c)
int isalpha (int __c)
int isascii (int __c)
int isblank (int __c)
int iscntrl (int __c)
int isdigit (int __c)
int isgraph (int __c)
int islower (int __c)
int isprint (int __c)
int ispunct (int __c)
int isspace (int __c)
int isupper (int __c)
int isxdigit (int __c)

so like, one by one, here's the whole roster 👇

• int isalnum (int __c) — is it a letter or a number? iconic either way 💖
• int isalpha (int __c) — is it a letter? alphabet girlie check ✨
• int isascii (int __c) — is it in the ASCII club? 🎀
• int isblank (int __c) — is it a blank character? soft launch energy 🌸
• int iscntrl (int __c) — is it a control character? the unhinged ones 😭
• int isdigit (int __c) — is it a digit? '0' through '9', inclusive, no cap 🔢
• int isgraph (int __c) — is it a graphical character? main character energy 👑
• int islower (int __c) — is it lowercase? soft-spoken queen 💜
• int isprint (int __c) — is it printable? it's giving visible 🌈
• int ispunct (int __c) — is it punctuation? the drama of it all 💅
• int isspace (int __c) — is it whitespace? personal space, respected 🦋
• int isupper (int __c) — is it uppercase? LOUD and proud 🔥
• int isxdigit (int __c) — is it a hex digit? nerd-coded and we love that ⭐

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🧚 Character convertion routines 🧚

this realization permits all possible values of the integer argument, fr fr. here's the tea:

• toascii() clears all highest bits 🧹
• tolower() and toupper() return an input argument as is if it is not an unsigned char value 🙈

int toascii (int __c)
int tolower (int __c)
int toupper (int __c)

so the lineup 💫

• int toascii (int __c) — clears all the highest bits, spring cleaning for your int ✨
• int tolower (int __c) — drops it to lowercase, but if it's not an unsigned char value it just returns your input as is, no notes 🍓
• int toupper (int __c) — yells it into uppercase, and same deal: not an unsigned char value? returns the input as is 💜

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✨ Author ✨

Generated automatically by Doxygen for avr-libc from the source code. (not a human, just a little robot doing its thing 🤖💖)

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k that's the whole page bestie, go forth and classify some characters 💅✨

Version 2.1.0 — Sat Jan 29 2022 🎀 mwah, love u, bye 🫶🌸