getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - nonlocking stdio functions

       For an explanation of the terms used in this section, see attributes(7).
       ┌──────────────────────┬───────────────┬────────────────────────────────────────────────────────────────┐
       │ Interface            │ Attribute     │ Value                                                          │
       ├──────────────────────┼───────────────┼────────────────────────────────────────────────────────────────┤
       │ getc_unlocked(),     │ Thread safety │ MT-Safe race:stream                                            │
       │ putc_unlocked(),     │               │                                                                │
       │ clearerr_unlocked(), │               │                                                                │
       │ fflush_unlocked(),   │               │                                                                │
       │ fgetc_unlocked(),    │               │                                                                │
       │ fputc_unlocked(),    │               │                                                                │
       │ fread_unlocked(),    │               │                                                                │
       │ fwrite_unlocked(),   │               │                                                                │
       │ fgets_unlocked(),    │               │                                                                │
       │ fputs_unlocked(),    │               │                                                                │
       │ getwc_unlocked(),    │               │                                                                │
       │ fgetwc_unlocked(),   │               │                                                                │
       │ fputwc_unlocked(),   │               │                                                                │
       │ putwc_unlocked(),    │               │                                                                │
       │ fgetws_unlocked(),   │               │                                                                │
       │ fputws_unlocked()    │               │                                                                │
       ├──────────────────────┼───────────────┼────────────────────────────────────────────────────────────────┤
       │ getchar_unlocked(),  │ Thread safety │ MT-Unsafe race:stdin                                           │
       │ getwchar_unlocked()  │               │                                                                │
       ├──────────────────────┼───────────────┼────────────────────────────────────────────────────────────────┤
       │ putchar_unlocked(),  │ Thread safety │ MT-Unsafe race:stdout                                          │
       │ putwchar_unlocked()  │               │                                                                │
       ├──────────────────────┼───────────────┼────────────────────────────────────────────────────────────────┤
       │ feof_unlocked(),     │ Thread safety │ MT-Safe                                                        │
       │ ferror_unlocked(),   │               │                                                                │
       │ fileno_unlocked()    │               │                                                                │
       └──────────────────────┴───────────────┴────────────────────────────────────────────────────────────────┘

       Each  of  these functions has the same behavior as its counterpart without the "_unlocked" suffix, except
       that they do not use locking (they do not set locks themselves, and do not test for the presence of locks
       set by others) and hence are thread-unsafe.  See flockfile(3).

getc_unlocked()
       getchar_unlocked()
       putc_unlocked()
       putchar_unlocked()
              POSIX.1-2001.

       Standard C library (libc, -lc)

       getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - nonlocking stdio functions

flockfile(3), stdio(3)

Linux man-pages 6.9.1                              2024-05-02                                  unlocked_stdio(3)

getc_unlocked()
       getchar_unlocked()
       putc_unlocked()
       putchar_unlocked()
              POSIX.1-2008.

       Others:
              None.

#include<stdio.h>intgetc_unlocked(FILE*stream);intgetchar_unlocked(void);intputc_unlocked(intc,FILE*stream);intputchar_unlocked(intc);voidclearerr_unlocked(FILE*stream);intfeof_unlocked(FILE*stream);intferror_unlocked(FILE*stream);intfileno_unlocked(FILE*stream);intfflush_unlocked(FILE*_Nullablestream);intfgetc_unlocked(FILE*stream);intfputc_unlocked(intc,FILE*stream);size_tfread_unlocked(voidptr[restrict.size*.n],size_tsize,size_tn,FILE*restrictstream);size_tfwrite_unlocked(constvoidptr[restrict.size*.n],size_tsize,size_tn,FILE*restrictstream);char*fgets_unlocked(chars[restrict.n],intn,FILE*restrictstream);intfputs_unlocked(constchar*restricts,FILE*restrictstream);#include<wchar.h>wint_tgetwc_unlocked(FILE*stream);wint_tgetwchar_unlocked(void);wint_tfgetwc_unlocked(FILE*stream);wint_tfputwc_unlocked(wchar_twc,FILE*stream);wint_tputwc_unlocked(wchar_twc,FILE*stream);wint_tputwchar_unlocked(wchar_twc);wchar_t*fgetws_unlocked(wchar_tws[restrict.n],intn,FILE*restrictstream);intfputws_unlocked(constwchar_t*restrictws,FILE*restrictstream);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getc_unlocked(), getchar_unlocked(), putc_unlocked(), putchar_unlocked():
           /* glibc >= 2.24: */ _POSIX_C_SOURCE >= 199309L
               || /* glibc <= 2.23: */ _POSIX_C_SOURCE
               || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

       clearerr_unlocked(),    feof_unlocked(),    ferror_unlocked(),    fileno_unlocked(),   fflush_unlocked(),
       fgetc_unlocked(), fputc_unlocked(), fread_unlocked(), fwrite_unlocked():
           /* glibc >= 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

       fgets_unlocked(),    fputs_unlocked(),    getwc_unlocked(),    getwchar_unlocked(),    fgetwc_unlocked(),
       fputwc_unlocked(), putwchar_unlocked(), fgetws_unlocked(), fputws_unlocked():
           _GNU_SOURCE