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 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 set_mempolicy – set default NUMA memory policy for a thread and its children SYNOPSIS #include <numaif.h> long set_mempolicy(int mode, const unsigned long *nodemask, unsigned long maxnode); Link with – lnuma. DESCRIPTION set_mempolicy() sets the NUMA memory policy of the calling thread, which consists of a policy mode and zero or more nodes, to the…
NAME send, sendto, sendmsg – send a message on a socket SYNOPSIS #include <sys/socket.h> #include <sys/types.h> ssize_t send(int sockfd, const void *buf, size_t len, int flags); ssize_t sendto(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen); ssize_t sendmsg(int sockfd, const struct msghdr *msg, int flags); DESCRIPTION The system calls…
NAME send, sendto, sendmsg – send a message on a socket SYNOPSIS #include <sys/socket.h> #include <sys/types.h> ssize_t send(int sockfd, const void *buf, size_t len, int flags); ssize_t sendto(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen); ssize_t sendmsg(int sockfd, const struct msghdr *msg, int flags); DESCRIPTION The system calls…
NAME sendmmsg – send multiple messages on a socket SYNOPSIS #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/socket.h> int sendmmsg(int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags); DESCRIPTION The sendmmsg() system call is an extension of sendmsg(2) that allows the caller to transmit multiple messages on a socket using a single system call….
NAME sendfile – transfer data between file descriptors SYNOPSIS #include <sys/sendfile.h> ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count); DESCRIPTION sendfile() copies data between one file descriptor and another. Because this copying is done within the kernel, sendfile() is more efficient than the combination of read(2) and write(2), which would require transferring data to…
NAME sendfile – transfer data between file descriptors SYNOPSIS #include <sys/sendfile.h> ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count); DESCRIPTION sendfile() copies data between one file descriptor and another. Because this copying is done within the kernel, sendfile() is more efficient than the combination of read(2) and write(2), which would require transferring data to…
NAME send, sendto, sendmsg – send a message on a socket SYNOPSIS #include <sys/socket.h> #include <sys/types.h> ssize_t send(int sockfd, const void *buf, size_t len, int flags); ssize_t sendto(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen); ssize_t sendmsg(int sockfd, const struct msghdr *msg, int flags); DESCRIPTION The system calls…
NAME semop, semtimedop – System V semaphore operations SYNOPSIS #include <sys/ipc.h> #include <sys/sem.h> #include <sys/types.h> int semop(int semid, struct sembuf *sops, size_t nsops); int semtimedop(int semid, struct sembuf *sops, size_t nsops, const struct timespec *timeout); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): semtimedop(): _GNU_SOURCE DESCRIPTION Each semaphore in a System V semaphore set has…
NAME semop, semtimedop – System V semaphore operations SYNOPSIS #include <sys/ipc.h> #include <sys/sem.h> #include <sys/types.h> int semop(int semid, struct sembuf *sops, size_t nsops); int semtimedop(int semid, struct sembuf *sops, size_t nsops, const struct timespec *timeout); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): semtimedop(): _GNU_SOURCE DESCRIPTION Each semaphore in a System V semaphore set has…
NAME semget – get a System V semaphore set identifier SYNOPSIS #include <sys/ipc.h> #include <sys/sem.h> #include <sys/types.h> int semget(key_t key, int nsems, int semflg); DESCRIPTION The semget() system call returns the System V semaphore set identifier associated with the argument key. It may be used either to obtain the identifier of a previously created semaphore…
NAME semctl – System V semaphore control operations SYNOPSIS #include <sys/ipc.h> #include <sys/sem.h> #include <sys/types.h> int semctl(int semid, int semnum, int cmd, …); DESCRIPTION semctl() performs the control operation specified by cmd on the System V semaphore set identified by semid, or on the semnum-th semaphore of that set. (The semaphores in a set are…
NAME select, pselect – synchronous I/O multiplexing SYNOPSIS See select(2) DESCRIPTION The select() and pselect() system calls are used to efficiently monitor multiple file descriptors, to see if any of them is, or becomes, "ready"; that is, to see whether I/O becomes possible, or an "exceptional condition" has occurred on any of the file descriptors….
NAME afs_syscall, break, fattach, fdetach, ftime, getmsg, getpmsg, gtty, isastream, lock, madvise1, mpx, prof, profil, putmsg, putpmsg, security, stty, tuxcall, ulimit, vserver – unimplemented system calls SYNOPSIS Unimplemented system calls. DESCRIPTION These system calls are not implemented in the Linux kernel. RETURN VALUE These system calls always return -1 and set errno to ENOSYS. NOTES…
NAME seccomp – operate on Secure Computing state of the process SYNOPSIS #include <linux/audit.h> #include <linux/filter.h> #include <linux/seccomp.h> #include <linux/signal.h> #include <sys/ptrace.h> int seccomp(unsigned int operation, unsigned int flags, void *args); DESCRIPTION The seccomp() system call operates on the Secure Computing (seccomp) state of the calling process. Currently, Linux supports the following operation values: SECCOMP_SET_MODE_STRICT…
NAME sched_yield – yield the processor SYNOPSIS #include <sched.h> int sched_yield(void); DESCRIPTION sched_yield() causes the calling thread to relinquish the CPU. The thread is moved to the end of the queue for its static priority and a new thread gets to run. RETURN VALUE On success, sched_yield() returns 0. On error, -1 is returned, and…
NAME sched_setscheduler, sched_getscheduler – set and get scheduling policy/parameters SYNOPSIS #include <sched.h> int sched_setscheduler(pid_t pid, int policy, const struct sched_param *param); int sched_getscheduler(pid_t pid); DESCRIPTION The sched_setscheduler() system call sets both the scheduling policy and parameters for the thread whose ID is specified in pid. If pid equals zero, the scheduling policy and parameters of…
NAME sched_setparam, sched_getparam – set and get scheduling parameters SYNOPSIS #include <sched.h> int sched_setparam(pid_t pid, const struct sched_param *param); int sched_getparam(pid_t pid, struct sched_param *param); struct sched_param { … int sched_priority; … }; DESCRIPTION sched_setparam() sets the scheduling parameters associated with the scheduling policy for the thread whose thread ID is specified in pid. If…
NAME sched_setattr, sched_getattr – set and get scheduling policy and attributes SYNOPSIS #include <sched.h> int sched_setattr(pid_t pid, struct sched_attr *attr, unsigned int flags); int sched_getattr(pid_t pid, struct sched_attr *attr, unsigned int size, unsigned int flags); DESCRIPTION sched_setattr() The sched_setattr() system call sets the scheduling policy and associated attributes for the thread whose ID is specified…
NAME sched_setaffinity, sched_getaffinity – set and get a thread’s CPU affinity mask SYNOPSIS #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sched.h> int sched_setaffinity(pid_t pid, size_t cpusetsize, const cpu_set_t *mask); int sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask); DESCRIPTION A thread’s CPU affinity mask determines the set of CPUs on which it is eligible to run. On…