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 fanotify_init – create and initialize fanotify group SYNOPSIS #include <fcntl.h> #include <sys/fanotify.h> int fanotify_init(unsigned int flags, unsigned int event_f_flags); DESCRIPTION For an overview of the fanotify API, see fanotify(7). fanotify_init() initializes a new fanotify group and returns a file descriptor for the event queue associated with the group. The file descriptor is used in…
NAME fallocate – manipulate file space SYNOPSIS #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h> int fallocate(int fd, int mode, off_t offset, off_t len); DESCRIPTION This is a nonportable, Linux-specific system call. For the portable, POSIX.1-specified method of ensuring that space is allocated for a file, see posix_fallocate(3). fallocate() allows the caller to directly manipulate…
NAME posix_fadvise – predeclare an access pattern for file data SYNOPSIS #include <fcntl.h> int posix_fadvise(int fd, off_t offset, off_t len, int advice); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): posix_fadvise(): _POSIX_C_SOURCE >= 200112L DESCRIPTION Programs can use posix_fadvise() to announce an intention to access file data in a specific pattern in the future, thus allowing the…
NAME posix_fadvise – predeclare an access pattern for file data SYNOPSIS #include <fcntl.h> int posix_fadvise(int fd, off_t offset, off_t len, int advice); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): posix_fadvise(): _POSIX_C_SOURCE >= 200112L DESCRIPTION Programs can use posix_fadvise() to announce an intention to access file data in a specific pattern in the future, thus allowing the…
NAME fadvise64,fadvise64_64 – Give advice about file access SYNOPSIS long fadvise64_64 (int fs, loff_t offset, loff_t len, int advice, int fs, loff_t offset, loff_t len, int advice); long sys_fadvise64 (int fs, loff_t offset, loff_t len, int advice, int fs, loff_t offset, loff_t len, int advice); DESCRIPTION Allows an application to to tell the kernel how it expects to use a file handle, so that the kernel can choose appropriate read-ahead and caching techniques…
NAME access, faccessat, faccessat2 – check user’s permissions for a file SYNOPSIS #include <unistd.h> int access(const char *pathname, int mode); #include <fcntl.h> /* Definition of AT_* constants */ #include <unistd.h> int faccessat(int dirfd, const char *pathname, int mode, int flags); /* But see C library/kernel differences, below */ int faccessat2(int dirfd, const char *pathname, int…
NAME access, faccessat, faccessat2 – check user’s permissions for a file SYNOPSIS #include <unistd.h> int access(const char *pathname, int mode); #include <fcntl.h> /* Definition of AT_* constants */ #include <unistd.h> int faccessat(int dirfd, const char *pathname, int mode, int flags); /* But see C library/kernel differences, below */ int faccessat2(int dirfd, const char *pathname, int…
NAME exit_group – exit all threads in a process SYNOPSIS #include <linux/unistd.h> void exit_group(int status); DESCRIPTION This system call is equivalent to _exit(2) except that it terminates not only the calling thread, but all threads in the calling process’s thread group. RETURN VALUE This system call does not return. VERSIONS This call is present since…
NAME _exit, _Exit – terminate the calling process SYNOPSIS #include <unistd.h> void _exit(int status); #include <stdlib.h> void _Exit(int status); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): _Exit(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L DESCRIPTION _exit() terminates the calling process "immediately". Any open file descriptors belonging to the process are closed. Any children of the process are inherited…
NAME execveat – execute program relative to a directory file descriptor SYNOPSIS #include <unistd.h> int execveat(int dirfd, const char *pathname, char *const argv[], char *const envp[], int flags); DESCRIPTION The execveat() system call executes the program referred to by the combination of dirfd and pathname. It operates in exactly the same way as execve(2), except…
NAME eventfd – create a file descriptor for event notification SYNOPSIS #include <sys/eventfd.h> int eventfd(unsigned int initval, int flags); DESCRIPTION eventfd() creates an "eventfd object" that can be used as an event wait/notify mechanism by user-space applications, and by the kernel to notify user-space applications of events. The object contains an unsigned 64-bit integer (uint64_t)…
NAME eventfd – create a file descriptor for event notification SYNOPSIS #include <sys/eventfd.h> int eventfd(unsigned int initval, int flags); DESCRIPTION eventfd() creates an "eventfd object" that can be used as an event wait/notify mechanism by user-space applications, and by the kernel to notify user-space applications of events. The object contains an unsigned 64-bit integer (uint64_t)…
NAME epoll_wait, epoll_pwait – wait for an I/O event on an epoll file descriptor SYNOPSIS #include <sys/epoll.h> int epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout); int epoll_pwait(int epfd, struct epoll_event *events, int maxevents, int timeout, const sigset_t *sigmask); DESCRIPTION The epoll_wait() system call waits for events on the epoll(7) instance referred to by…
NAME epoll_wait, epoll_pwait – wait for an I/O event on an epoll file descriptor SYNOPSIS #include <sys/epoll.h> int epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout); int epoll_pwait(int epfd, struct epoll_event *events, int maxevents, int timeout, const sigset_t *sigmask); DESCRIPTION The epoll_wait() system call waits for events on the epoll(7) instance referred to by…
NAME epoll_ctl – control interface for an epoll file descriptor SYNOPSIS #include <sys/epoll.h> int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event); DESCRIPTION This system call is used to add, modify, or remove entries in the interest list of the epoll(7) instance referred to by the file descriptor epfd. It requests that the operation…
NAME epoll_create, epoll_create1 – open an epoll file descriptor SYNOPSIS #include <sys/epoll.h> int epoll_create(int size); int epoll_create1(int flags); DESCRIPTION epoll_create() creates a new epoll(7) instance. Since Linux 2.6.8, the size argument is ignored, but must be greater than zero; see NOTES. epoll_create() returns a file descriptor referring to the new epoll instance. This file descriptor…
NAME epoll_create, epoll_create1 – open an epoll file descriptor SYNOPSIS #include <sys/epoll.h> int epoll_create(int size); int epoll_create1(int flags); DESCRIPTION epoll_create() creates a new epoll(7) instance. Since Linux 2.6.8, the size argument is ignored, but must be greater than zero; see NOTES. epoll_create() returns a file descriptor referring to the new epoll instance. This file descriptor…
NAME dup, dup2, dup3 – duplicate a file descriptor SYNOPSIS #include <unistd.h> int dup(int oldfd); int dup2(int oldfd, int newfd); #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h> /* Obtain O_* constant definitions */ #include <unistd.h> int dup3(int oldfd, int newfd, int flags); DESCRIPTION The dup() system call creates a copy of the file descriptor…
NAME dup, dup2, dup3 – duplicate a file descriptor SYNOPSIS #include <unistd.h> int dup(int oldfd); int dup2(int oldfd, int newfd); #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h> /* Obtain O_* constant definitions */ #include <unistd.h> int dup3(int oldfd, int newfd, int flags); DESCRIPTION The dup() system call creates a copy of the file descriptor…
NAME delete_module – unload a kernel module SYNOPSIS int delete_module(const char *name, int flags); Note: No declaration of this system call is provided in glibc headers; see NOTES. DESCRIPTION The delete_module() system call attempts to remove the unused loadable module entry identified by name. If the module has an exit function, then that function is…