The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
NAME getdents, getdents64 – get directory entries SYNOPSIS long getdents(unsigned int fd, struct linux_dirent *dirp, unsigned int count); #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <dirent.h> ssize_t getdents64(int fd, void *dirp, size_t count); Note: There is no glibc wrapper for getdents(); see NOTES. DESCRIPTION These are not the interfaces you are interested in. Look at…
NAME getcwd, getwd, get_current_dir_name – get current working directory SYNOPSIS #include <unistd.h> char *getcwd(char *buf, size_t size); char *getwd(char *buf); char *get_current_dir_name(void); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): get_current_dir_name(): _GNU_SOURCE getwd(): Since glibc 2.12: (_XOPEN_SOURCE >= 500) && !(_POSIX_C_SOURCE & nbsp; >= 200809L) || /* Glibc since 2.19: */ _DEFAULT_SOURCE…
NAME getcpu – determine CPU and NUMA node on which the calling thread is running SYNOPSIS #include <linux/getcpu.h> int getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache); DESCRIPTION The getcpu() system call identifies the processor and node on which the calling thread or process is currently running and writes them into the integers pointed to by…
NAME getcontext, setcontext – get or set the user context SYNOPSIS #include <ucontext.h> int getcontext(ucontext_t *ucp); int setcontext(const ucontext_t *ucp); DESCRIPTION In a System V-like environment, one has the two types mcontext_t and ucontext_t defined in <ucontext.h> and the four functions getcontext(), setcontext(), makecontext(3), and swapcontext(3) that allow user-level context switching between multiple threads of…
NAME get_thread_area, set_thread_area – manipulate thread-local storage information SYNOPSIS #include <linux/unistd.h> #if defined __i386__ || defined __x86_64__ #include <asm/ldt.h> int get_thread_area(struct user_desc *u_info); int set_thread_area(struct user_desc *u_info); #elif defined __m68k__ int get_thread_area(void); int set_thread_area(unsigned long tp); #elif defined __mips__ int set_thread_area(unsigned long addr); #endif Note: There are no glibc wrappers for these system calls; see…
NAME get_robust_list, set_robust_list – get/set list of robust futexes SYNOPSIS #include <linux/futex.h> #include <sys/types.h> #include <syscall.h> long get_robust_list(int pid, struct robust_list_head **head_ptr, size_t *len_ptr); long set_robust_list(struct robust_list_head *head, size_t len); Note: There are no glibc wrappers for these system calls; see NOTES. DESCRIPTION These system calls deal with per-thread robust futex lists. These lists are…
NAME get_mempolicy – retrieve NUMA memory policy for a thread SYNOPSIS #include <numaif.h> long get_mempolicy(int *mode, unsigned long *nodemask, unsigned long maxnode, void *addr, unsigned long flags); Link with – lnuma. DESCRIPTION get_mempolicy() retrieves the NUMA policy of the calling thread or of a memory address, depending on the setting of flags. A NUMA machine…
NAME get_kernel_syms – retrieve exported kernel and module symbols SYNOPSIS #include <linux/module.h> int get_kernel_syms(struct kernel_sym *table); Note: No declaration of this system call is provided in glibc headers; see NOTES. DESCRIPTION Note: This system call is present only in kernels before Linux 2.6. If table is NULL, get_kernel_syms() returns the number of symbols available for…
NAME futimesat – change timestamps of a file relative to a directory file descriptor SYNOPSIS #include <fcntl.h> /* Definition of AT_* constants */ #include <sys/time.h> int futimesat(int dirfd, const char *pathname, const struct timeval times[2]); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): futimesat(): _GNU_SOURCE DESCRIPTION This system call is obsolete. Use utimensat(2) instead. The…
NAME futex – fast user-space locking SYNOPSIS #include <linux/futex.h> #include <stdint.h> #include <sys/time.h> long futex(uint32_t *uaddr, int futex_op, uint32_t val, const struct timespec *timeout, /* or: uint32_t val2 */ uint32_t *uaddr2, uint32_t val3); Note: There is no glibc wrapper for this system call; see NOTES. DESCRIPTION The futex() system call provides a method for waiting…
NAME truncate, ftruncate – truncate a file to a specified length SYNOPSIS #include <unistd.h> #include <sys/types.h> int truncate(const char *path, off_t length); int ftruncate(int fd, off_t length); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): truncate(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L || /* Glibc versions <= 2.19: */ _BSD_SOURCE ftruncate(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.3.5: */ _POSIX_C_SOURCE >= 200112L || /* Glibc versions <= 2.19: */ _BSD_SOURCE DESCRIPTION The truncate() and ftruncate() functions…
NAME truncate, ftruncate – truncate a file to a specified length SYNOPSIS #include <unistd.h> #include <sys/types.h> int truncate(const char *path, off_t length); int ftruncate(int fd, off_t length); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): truncate(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L || /* Glibc versions <= 2.19: */ _BSD_SOURCE ftruncate(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.3.5: */ _POSIX_C_SOURCE >= 200112L || /* Glibc versions <= 2.19: */ _BSD_SOURCE DESCRIPTION The truncate() and ftruncate() functions…
NAME fsync, fdatasync – synchronize a file’s in-core state with storage device SYNOPSIS #include <unistd.h> int fsync(int fd); int fdatasync(int fd); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): fsync(): Glibc 2.16 and later: No feature test macros need be defined Glibc up to and including 2.15: _BSD_SOURCE || _XOPEN_SOURCE || /* since glibc 2.8: */ _POSIX_C_SOURCE >= 200112L fdatasync(): _POSIX_C_SOURCE >= 199309L || _XOPEN_SOURCE >= 500…
NAME statvfs, fstatvfs – get filesystem statistics SYNOPSIS #include <sys/statvfs.h> int statvfs(const char *path, struct statvfs *buf); int fstatvfs(int fd, struct statvfs *buf); DESCRIPTION The function statvfs() returns information about a mounted filesystem. path is the pathname of any file within the mounted filesystem. buf is a pointer to a statvfs structure defined approximately as…
NAME statfs, fstatfs – get filesystem statistics SYNOPSIS #include <sys/vfs.h> /* or <sys/statfs.h> */ int statfs(const char *path, struct statfs *buf); int fstatfs(int fd, struct statfs *buf); DESCRIPTION The statfs() system call returns information about a mounted filesystem. path is the pathname of any file within the mounted filesystem. buf is a pointer to a…
NAME statfs, fstatfs – get filesystem statistics SYNOPSIS #include <sys/vfs.h> /* or <sys/statfs.h> */ int statfs(const char *path, struct statfs *buf); int fstatfs(int fd, struct statfs *buf); DESCRIPTION The statfs() system call returns information about a mounted filesystem. path is the pathname of any file within the mounted filesystem. buf is a pointer to a…
NAME stat, fstat, lstat, fstatat – get file status SYNOPSIS #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> int stat(const char *pathname, struct stat *statbuf); int fstat(int fd, struct stat *statbuf); int lstat(const char *pathname, struct stat *statbuf); #include <fcntl.h> /* Definition of AT_* constants */ #include <sys/stat.h> int fstatat(int dirfd, const char *pathname, struct stat *statbuf,…
NAME stat, fstat, lstat, fstatat – get file status SYNOPSIS #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> int stat(const char *pathname, struct stat *statbuf); int fstat(int fd, struct stat *statbuf); int lstat(const char *pathname, struct stat *statbuf); #include <fcntl.h> /* Definition of AT_* constants */ #include <sys/stat.h> int fstatat(int dirfd, const char *pathname, struct stat *statbuf,…
NAME stat, fstat, lstat, fstatat – get file status SYNOPSIS #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> int stat(const char *pathname, struct stat *statbuf); int fstat(int fd, struct stat *statbuf); int lstat(const char *pathname, struct stat *statbuf); #include <fcntl.h> /* Definition of AT_* constants */ #include <sys/stat.h> int fstatat(int dirfd, const char *pathname, struct stat *statbuf,…
NAME stat, fstat, lstat, fstatat – get file status SYNOPSIS #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> int stat(const char *pathname, struct stat *statbuf); int fstat(int fd, struct stat *statbuf); int lstat(const char *pathname, struct stat *statbuf); #include <fcntl.h> /* Definition of AT_* constants */ #include <sys/stat.h> int fstatat(int dirfd, const char *pathname, struct stat *statbuf,…