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.
splice – splice data to/from a pipe Synopsis#define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h> ssize_t splice(int fd_in, loff_t *off_in, int fd_out, loff_t *off_out, size_t len, unsigned int flags);Descriptionsplice() moves data between two file descriptors without copying between kernel address space and user address space. It transfers up to len bytes of data from the…
socketpair – create a pair of connected sockets Synopsis#include <sys/types.h> /* See NOTES */ #include <sys/socket.h> int socketpair(int domain, int type, int protocol, int sv[2]); DescriptionThe socketpair() call creates an unnamed pair of connected sockets in the specified domain, of the specified type, and using the optionally specified protocol. For further details of these arguments,…
socketcall – socket system calls Synopsis#include <linux/net.h> int socketcall(int call, unsigned long *args); Descriptionsocketcall() is a common kernel entry point for the socket system calls. call determines which socket function to invoke. args points to a block containing the actual arguments, which are passed through to the appropriate call. User programs should call the appropriate…
sigwaitinfo, sigtimedwait, rt_sigtimedwait – synchronously wait for queued signals Synopsis#include <signal.h> int sigwaitinfo(const sigset_t *set, siginfo_t *info); int sigtimedwait(const sigset_t *set, siginfo_t *info, const struct timespec *timeout);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigwaitinfo(), sigtimedwait(): _POSIX_C_SOURCE >= 199309L Descriptionsigwaitinfo() suspends execution of the calling thread until one of the signals in set is pending (If one…
sigwaitinfo, sigtimedwait, rt_sigtimedwait – synchronously wait for queued signals Synopsis#include <signal.h> int sigwaitinfo(const sigset_t *set, siginfo_t *info); int sigtimedwait(const sigset_t *set, siginfo_t *info, const struct timespec *timeout);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigwaitinfo(), sigtimedwait(): _POSIX_C_SOURCE >= 199309L Descriptionsigwaitinfo() suspends execution of the calling thread until one of the signals in set is pending (If one…
sigsuspend, rt_sigsuspend – wait for a signal Synopsis#include <signal.h> int sigsuspend(const sigset_t *mask); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigsuspend(): _POSIX_C_SOURCE Descriptionsigsuspend() temporarily replaces the signal mask of the calling thread with the mask given by mask and then suspends the thread until delivery of a signal whose action is to invoke a…
sigreturn, rt_sigreturn – return from signal handler and cleanup stack frame Synopsisint sigreturn(…); DescriptionIf the Linux kernel determines that an unblocked signal is pending for a process, then, at the next transition back to user mode in that process (e.g., upon return from a system call or when the process is rescheduled onto the CPU),…
sigqueue – queue a signal and data to a process Synopsis#include <signal.h> int sigqueue(pid_t pid, int sig, const union sigval value); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigqueue(): _POSIX_C_SOURCE >= 199309L Descriptionsigqueue() sends the signal specified in sig to the process whose PID is given in pid. The permissions required to send a signal are…
sigprocmask, rt_sigprocmask – examine and change blocked signals Synopsis#include <signal.h> /* Prototype for the glibc wrapper function */ int sigprocmask(int how, const sigset_t *set, sigset_t *oldset); /* Prototype for the underlying system call */ int rt_sigprocmask(int how, const kernel_sigset_t *set, kernel_sigset_t *oldset, size_t sigsetsize); /* Prototype for the legacy system call (deprecated) */ int sigprocmask(int…
sigpending, rt_sigpending – examine pending signals Synopsis#include <signal.h> int sigpending(sigset_t *set); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigpending(): _POSIX_C_SOURCE Descriptionsigpending() returns the set of signals that are pending for delivery to the calling thread (i.e., the signals which have been raised while blocked). The mask of pending signals is returned in set. Return…
signalfd – create a file descriptor for accepting signals Synopsis#include <sys/signalfd.h> int signalfd(int fd, const sigset_t *mask, int flags); Descriptionsignalfd() creates a file descriptor that can be used to accept signals targeted at the caller. This provides an alternative to the use of a signal handler or sigwaitinfo(2), and has the advantage that the file…
signalfd – create a file descriptor for accepting signals Synopsis#include <sys/signalfd.h> int signalfd(int fd, const sigset_t *mask, int flags); Descriptionsignalfd() creates a file descriptor that can be used to accept signals targeted at the caller. This provides an alternative to the use of a signal handler or sigwaitinfo(2), and has the advantage that the file…
signal – ANSI C signal handling Synopsis#include <signal.h> typedef void (*sighandler_t)(int); sighandler_t signal(int signum, sighandler_t handler); DescriptionWARNING: the behavior of signal() varies across UNIX versions, and has also varied historically across different versions of Linux. Avoid its use: use sigaction(2) instead. See Portability below. signal() sets the disposition of the signal signum to handler, which…
sigaltstack – set and/or get signal stack context Synopsis#include <signal.h> int sigaltstack(const stack_t *ss, stack_t *old_ss); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigaltstack(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L || /* Glibc versions <= 2.19: */ _BSD_SOURCEDescriptionsigaltstack() allows a thread to define a new alternate signal stack and/or retrieve the state of an existing alternate signal stack. An alternate signal stack…
sigaction, rt_sigaction – examine and change a signal action Synopsis#include <signal.h> int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigaction(): _POSIX_C_SOURCE siginfo_t: _POSIX_C_SOURCE >= 199309L DescriptionThe sigaction() system call is used to change the action taken by a process on receipt of a specific signal. (See…
shutdown – shut down part of a full-duplex connection Synopsis#include <sys/socket.h> int shutdown(int sockfd, int how); DescriptionThe shutdown() call causes all or part of a full-duplex connection on the socket associated with sockfd to be shut down. If how is SHUT_RD, further receptions will be disallowed. If how is SHUT_WR, further transmissions will be disallowed….
shmat, shmdt – System V shared memory operations Synopsis#include <sys/types.h> #include <sys/shm.h> void *shmat(int shmid, const void *shmaddr, int shmflg); int shmdt(const void *shmaddr);Descriptionshmat()shmat() attaches the System V shared memory segment identified by shmid to the address space of the calling process. The attaching address is specified by shmaddr with one of the following criteria:…
shmget – allocates a System V shared memory segment Synopsis#include <sys/ipc.h> #include <sys/shm.h> int shmget(key_t key, size_t size, int shmflg); Descriptionshmget() returns the identifier of the System V shared memory segment associated with the value of the argument key. It may be used either to obtain the identifier of a previously created shared memory segment…
shmat, shmdt – System V shared memory operations Synopsis#include <sys/types.h> #include <sys/shm.h> void *shmat(int shmid, const void *shmaddr, int shmflg); int shmdt(const void *shmaddr);Descriptionshmat()shmat() attaches the System V shared memory segment identified by shmid to the address space of the calling process. The attaching address is specified by shmaddr with one of the following criteria:…
shmctl – System V shared memory control Synopsis#include <sys/ipc.h> #include <sys/shm.h> int shmctl(int shmid, int cmd, struct shmid_ds *buf); Descriptionshmctl() performs the control operation specified by cmd on the System V shared memory segment whose identifier is given in shmid. The buf argument is a pointer to a shmid_ds structure, defined in <sys/shm.h> as follows:…