Section 3: library functions
NAME getfilecon, fgetfilecon, lgetfilecon – get SELinux security context of a file SYNOPSIS #include <selinux/selinux.h> int getfilecon(const char *path, char **con); int getfilecon_raw(const char *path, char **con); int lgetfilecon(const char *path, char **con); int lgetfilecon_raw(const char *path, char **con); int fgetfilecon(int fd, char **con); int fgetfilecon_raw(int fd, char **con); DESCRIPTION getfilecon() retrieves the context associated…
NAME getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked – nonlocking stdio functions SYNOPSIS #include <stdio.h> int getc_unlocked(FILE *stream); int getchar_unlocked(void); int putc_unlocked(int c, FILE *stream); int putchar_unlocked(int c); void clearerr_unlocked(FILE *stream); int feof_unlocked(FILE *stream); int ferror_unlocked(FILE *stream); int fileno_unlocked(FILE *stream); int fflush_unlocked(FILE *stream); int fgetc_unlocked(FILE *stream); int fputc_unlocked(int c, FILE *stream); size_t fread_unlocked(void *ptr, size_t size, size_t n,…
NAME fgetc, fgets, getc, getchar, ungetc – input of characters and strings SYNOPSIS #include <stdio.h> int fgetc(FILE *stream); char *fgets(char *s, int size, FILE *stream); int getc(FILE *stream); int getchar(void); int ungetc(int c, FILE *stream); DESCRIPTION fgetc() reads the next character from stream and returns it as an unsigned char cast to an int, or…
NAME ffs, ffsl, ffsll – find first bit set in a word SYNOPSIS #include <strings.h> int ffs(int i); #include <string.h> int ffsl(long i); int ffsll(long long i); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): ffs(): Since glibc 2.12: _XOPEN_SOURCE >= 700 || ! (_POSIX_C_SOURCE >= 200809L) || /* Glibc since 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE Before glibc 2.12: none ffsl(), ffsll(): Since glibc…
NAME ffs, ffsl, ffsll – find first bit set in a word SYNOPSIS #include <strings.h> int ffs(int i); #include <string.h> int ffsl(long i); int ffsll(long long i); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): ffs(): Since glibc 2.12: _XOPEN_SOURCE >= 700 || ! (_POSIX_C_SOURCE >= 200809L) || /* Glibc since 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE Before glibc 2.12: none ffsl(), ffsll(): Since glibc…
NAME ffs, ffsl, ffsll – find first bit set in a word SYNOPSIS #include <strings.h> int ffs(int i); #include <string.h> int ffsl(long i); int ffsll(long long i); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): ffs(): Since glibc 2.12: _XOPEN_SOURCE >= 700 || ! (_POSIX_C_SOURCE >= 200809L) || /* Glibc since 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE Before glibc 2.12: none ffsl(), ffsll(): Since glibc…
NAME getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked – nonlocking stdio functions SYNOPSIS #include <stdio.h> int getc_unlocked(FILE *stream); int getchar_unlocked(void); int putc_unlocked(int c, FILE *stream); int putchar_unlocked(int c); void clearerr_unlocked(FILE *stream); int feof_unlocked(FILE *stream); int ferror_unlocked(FILE *stream); int fileno_unlocked(FILE *stream); int fflush_unlocked(FILE *stream); int fgetc_unlocked(FILE *stream); int fputc_unlocked(int c, FILE *stream); size_t fread_unlocked(void *ptr, size_t size, size_t n,…
NAME fflush – flush a stream SYNOPSIS #include <stdio.h> int fflush(FILE *stream); DESCRIPTION For output streams, fflush() forces a write of all user-space buffered data for the given output or update stream via the stream’s underlying write function. For input streams associated with seekable files (e.g., disk files, but not pipes or terminals), fflush() discards…
NAME ffi_prep_cif_var – Prepare a ffi_cif structure for use with ffi_call for variadic functions. SYNOPSIS In ffi.h Ft ffi_status Fo ffi_prep_cif_var Fa ffi_cif *cif Fa ffi_abi abi Fa unsigned int nfixedargs Fa unsigned int ntotalargs Fa ffi_type *rtype Fa ffi_type **atypes Fc DESCRIPTION The ffi_prep_cif_var function prepares a ffi_cif structure for use with ffi_call for…
NAME ffi_prep_cif – Prepare a ffi_cif structure for use with ffi_call SYNOPSIS In ffi.h Ft ffi_status Fo ffi_prep_cif Fa ffi_cif *cif Fa ffi_abi abi Fa unsigned int nargs Fa ffi_type *rtype Fa ffi_type **atypes Fc DESCRIPTION The ffi_prep_cif function prepares a ffi_cif structure for use with ffi_call Fa abi specifies a set of calling conventions…
NAME ffi_call – Invoke a foreign function. SYNOPSIS In ffi.h Ft void Fo ffi_call Fa ffi_cif *cif Fa void (*fn)(void) Fa void *rvalue Fa void **avalue Fc DESCRIPTION The ffi_call function provides a simple mechanism for invoking a function without requiring knowledge of the function’s interface at compile time. Fa fn is called with the…
NAME FFI – Foreign Function Interface LIBRARY libffi, -lffi SYNOPSIS In ffi.h Ft ffi_status Fo ffi_prep_cif Fa ffi_cif *cif Fa ffi_abi abi Fa unsigned int nargs Fa ffi_type *rtype Fa ffi_type **atypes Fc Ft void Fo ffi_prep_cif_var Fa ffi_cif *cif Fa ffi_abi abi Fa unsigned int nfixedargs Fa unsigned int ntotalargs Fa ffi_type *rtype Fa…
NAME vacall – C functions called with variable arguments SYNOPSIS #include <vacall.h> extern void* vacall_function; void function(alist) va_alist alist; { va_start_type(alist[, return_type]); arg = va_arg_type(alist[, arg_type]); va_return_type(alist[[, return_type ], return_value]); } vacall_function = &function; val = ((return_type (*) ()) vacall) (arg1,arg2,…); DESCRIPTION This set of macros permit a C function function to be called with…
NAME trampoline – closures as first-class C functions SYNOPSIS #include <trampoline_r.h> function = alloc_trampoline_r(address, data0, data1); free_trampoline_r(function); is_trampoline_r(function) trampoline_r_address(function) trampoline_r_data0(function) trampoline_r_data1(function) DESCRIPTION These functions implement closures as first-class C functions. A closure consists of a regular C function and a piece of data which gets passed to the C function when the closure is called….
NAME trampoline – closures as first-class C functions SYNOPSIS #include <trampoline.h> function = alloc_trampoline(address, variable, data); free_trampoline(function); is_trampoline(function) trampoline_address(function) trampoline_variable(function) trampoline_data(function) DESCRIPTION These functions implement closures as first-class C functions. A closure consists of a regular C function and a piece of data which gets passed to the C function when the closure is called….
NAME callback – closures with variable arguments as first-class C functions SYNOPSIS #include <callback.h> void function(data, alist) void *data; va_alist alist; { va_start_type(alist[, return_type]); arg = va_arg_type(alist[, arg_type]); va_return_type(alist[[, return_type ], return_value]); } callback = alloc_callback(&function, data); free_callback(callback); is_callback(callback) callback_address(callback) callback_data(callback) DESCRIPTION These functions implement closures with variable arguments as first-class C functions. Closures as…
NAME avcall – build a C argument list incrementally and call a C function on it. SYNOPSIS #include <avcall.h> av_alist alist; av_start_type(alist, &func [[, return_type], &return_value]); av_type(alist, [arg_type,] value); av_call(alist); DESCRIPTION This set of macros builds an argument list for a C function and calls the function on it. It significantly reduces the amount of…
NAME fexecve – execute program specified via file descriptor SYNOPSIS #include <unistd.h> int fexecve(int fd, char *const argv[], char *const envp[]); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): fexecve(): Since glibc 2.10: _POSIX_C_SOURCE >= 200809L Before glibc 2.10: _GNU_SOURCE DESCRIPTION fexecve() performs the same task as execve(2), with the difference that the file to be executed…
NAME system_data_types – overview of system data types DESCRIPTION aiocb Include: <aio.h>. struct aiocb { int aio_fildes; /* File descriptor */ off_t aio_offset; /* File offset */ volatile void *aio_buf; /* Location of buffer */ size_t aio_nbytes; /* Length of transfer */ int aio_reqprio; /* Request priority offset */ struct sigevent aio_sigevent; /* Signal number and value */ int aio_lio_opcode;/* Operation to be performed */ }; For further information about this structure, see aio(7). Conforming to: POSIX.1-2001 and later. See also:…
NAME feclearexcept, fegetexceptflag, feraiseexcept, fesetexceptflag, fetestexcept, fegetenv, fegetround, feholdexcept, fesetround, fesetenv, feupdateenv, feenableexcept, fedisableexcept, fegetexcept – floating-point rounding and exception handling SYNOPSIS #include <fenv.h> int feclearexcept(int excepts); int fegetexceptflag(fexcept_t *flagp, int excepts); int feraiseexcept(int excepts); int fesetexceptflag(const fexcept_t *flagp, int excepts); int fetestexcept(int excepts); int fegetround(void); int fesetround(int rounding_mode); int fegetenv(fenv_t *envp); int feholdexcept(fenv_t *envp);…