1unlocked_stdio(3) Library Functions Manual unlocked_stdio(3)
2
3
4
6 getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - non‐
7 locking stdio functions
8
10 Standard C library (libc, -lc)
11
13 #include <stdio.h>
14
15 int getc_unlocked(FILE *stream);
16 int getchar_unlocked(void);
17 int putc_unlocked(int c, FILE *stream);
18 int putchar_unlocked(int c);
19
20 void clearerr_unlocked(FILE *stream);
21 int feof_unlocked(FILE *stream);
22 int ferror_unlocked(FILE *stream);
23 int fileno_unlocked(FILE *stream);
24 int fflush_unlocked(FILE *stream);
25
26 int fgetc_unlocked(FILE *stream);
27 int fputc_unlocked(int c, FILE *stream);
28
29 size_t fread_unlocked(void ptr[restrict .size * .n],
30 size_t size, size_t n,
31 FILE *restrict stream);
32 size_t fwrite_unlocked(const void ptr[restrict .size * .n],
33 size_t size, size_t n,
34 FILE *restrict stream);
35
36 char *fgets_unlocked(char s[restrict .n], int n, FILE *restrict stream);
37 int fputs_unlocked(const char *restrict s, FILE *restrict stream);
38
39 #include <wchar.h>
40
41 wint_t getwc_unlocked(FILE *stream);
42 wint_t getwchar_unlocked(void);
43 wint_t fgetwc_unlocked(FILE *stream);
44
45 wint_t fputwc_unlocked(wchar_t wc, FILE *stream);
46 wint_t putwc_unlocked(wchar_t wc, FILE *stream);
47 wint_t putwchar_unlocked(wchar_t wc);
48
49 wchar_t *fgetws_unlocked(wchar_t ws[restrict .n], int n,
50 FILE *restrict stream);
51 int fputws_unlocked(const wchar_t *restrict ws,
52 FILE *restrict stream);
53
54 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
55
56 getc_unlocked(), getchar_unlocked(), putc_unlocked(),
57 putchar_unlocked():
58 /* glibc >= 2.24: */ _POSIX_C_SOURCE >= 199309L
59 || /* glibc <= 2.23: */ _POSIX_C_SOURCE
60 || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
61
62 clearerr_unlocked(), feof_unlocked(), ferror_unlocked(),
63 fileno_unlocked(), fflush_unlocked(), fgetc_unlocked(),
64 fputc_unlocked(), fread_unlocked(), fwrite_unlocked():
65 /* glibc >= 2.19: */ _DEFAULT_SOURCE
66 || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
67
68 fgets_unlocked(), fputs_unlocked(), getwc_unlocked(),
69 getwchar_unlocked(), fgetwc_unlocked(), fputwc_unlocked(),
70 putwchar_unlocked(), fgetws_unlocked(), fputws_unlocked():
71 _GNU_SOURCE
72
74 Each of these functions has the same behavior as its counterpart with‐
75 out the "_unlocked" suffix, except that they do not use locking (they
76 do not set locks themselves, and do not test for the presence of locks
77 set by others) and hence are thread-unsafe. See flockfile(3).
78
80 For an explanation of the terms used in this section, see at‐
81 tributes(7).
82
83 ┌─────────────────────┬───────────────┬────────────────────────────────┐
84 │Interface │ Attribute │ Value │
85 ├─────────────────────┼───────────────┼────────────────────────────────┤
86 │getc_unlocked(), │ Thread safety │ MT-Safe race:stream │
87 │putc_unlocked(), │ │ │
88 │clearerr_unlocked(), │ │ │
89 │fflush_unlocked(), │ │ │
90 │fgetc_unlocked(), │ │ │
91 │fputc_unlocked(), │ │ │
92 │fread_unlocked(), │ │ │
93 │fwrite_unlocked(), │ │ │
94 │fgets_unlocked(), │ │ │
95 │fputs_unlocked(), │ │ │
96 │getwc_unlocked(), │ │ │
97 │fgetwc_unlocked(), │ │ │
98 │fputwc_unlocked(), │ │ │
99 │putwc_unlocked(), │ │ │
100 │fgetws_unlocked(), │ │ │
101 │fputws_unlocked() │ │ │
102 ├─────────────────────┼───────────────┼────────────────────────────────┤
103 │getchar_unlocked(), │ Thread safety │ MT-Unsafe race:stdin │
104 │getwchar_unlocked() │ │ │
105 ├─────────────────────┼───────────────┼────────────────────────────────┤
106 │putchar_unlocked(), │ Thread safety │ MT-Unsafe race:stdout │
107 │putwchar_unlocked() │ │ │
108 ├─────────────────────┼───────────────┼────────────────────────────────┤
109 │feof_unlocked(), │ Thread safety │ MT-Safe │
110 │ferror_unlocked(), │ │ │
111 │fileno_unlocked() │ │ │
112 └─────────────────────┴───────────────┴────────────────────────────────┘
113
115 getc_unlocked()
116 getchar_unlocked()
117 putc_unlocked()
118 putchar_unlocked()
119 POSIX.1-2008.
120
121 Others:
122 None.
123
125 getc_unlocked()
126 getchar_unlocked()
127 putc_unlocked()
128 putchar_unlocked()
129 POSIX.1-2001.
130
132 flockfile(3), stdio(3)
133
134
135
136Linux man-pages 6.04 2023-03-30 unlocked_stdio(3)