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 create_module – create a loadable module entry SYNOPSIS #include <linux/module.h> caddr_t create_module(const char *name, size_t size); 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. create_module() attempts to create a loadable module entry and reserve the…
NAME open, openat, creat – open and possibly create a file SYNOPSIS #include <fcntl.h> #include <sys/stat.h> #include <sys/types.h> int open(const char *pathname, int flags); int open(const char *pathname, int flags, mode_t mode); int creat(const char *pathname, mode_t mode); int openat(int dirfd, const char *pathname, int flags); int openat(int dirfd, const char *pathname, int flags, mode_t…
NAME copy_file_range – Copy a range of data from one file to another SYNOPSIS #define _GNU_SOURCE #include <unistd.h> ssize_t copy_file_range(int fd_in, loff_t *off_in, int fd_out, loff_t *off_out, size_t len, unsigned int flags); DESCRIPTION The copy_file_range() system call performs an in-kernel copy between two file descriptors without the additional cost of transferring data from the kernel…
NAME clone, __clone2, clone3 – create a child process SYNOPSIS /* Prototype for the glibc wrapper function */ #define _GNU_SOURCE #include <sched.h> int clone(int (*fn)(void *), void *stack, int flags, void *arg, … /* pid_t *parent_tid, void *tls, pid_t *child_tid */); /* For the prototype of the raw clone() system call, see NOTES */ long…
NAME clone, __clone2, clone3 – create a child process SYNOPSIS /* Prototype for the glibc wrapper function */ #define _GNU_SOURCE #include <sched.h> int clone(int (*fn)(void *), void *stack, int flags, void *arg, … /* pid_t *parent_tid, void *tls, pid_t *child_tid */); /* For the prototype of the raw clone() system call, see NOTES */ long…
NAME clone, __clone2, clone3 – create a child process SYNOPSIS /* Prototype for the glibc wrapper function */ #define _GNU_SOURCE #include <sched.h> int clone(int (*fn)(void *), void *stack, int flags, void *arg, … /* pid_t *parent_tid, void *tls, pid_t *child_tid */); /* For the prototype of the raw clone() system call, see NOTES */ long…
NAME clock_getres, clock_gettime, clock_settime – clock and time functions SYNOPSIS #include <time.h> int clock_getres(clockid_t clockid, struct timespec *res); int clock_gettime(clockid_t clockid, struct timespec *tp); int clock_settime(clockid_t clockid, const struct timespec *tp); Link with -lrt (only for glibc versions before 2.17). Feature Test Macro Requirements for glibc (see feature_test_macros(7)): clock_getres(), clock_gettime(), clock_settime(): _POSIX_C_SOURCE >= 199309L DESCRIPTION The function…
NAME clock_nanosleep – high-resolution sleep with specifiable clock SYNOPSIS #include <time.h> int clock_nanosleep(clockid_t clockid, int flags, const struct timespec *request, struct timespec *remain); Link with -lrt (only for glibc versions before 2.17). Feature Test Macro Requirements for glibc (see feature_test_macros(7)): clock_nanosleep(): _POSIX_C_SOURCE >= 200112L DESCRIPTION Like nanosleep(2), clock_nanosleep() allows the calling thread to sleep for an interval…
NAME clock_getres, clock_gettime, clock_settime – clock and time functions SYNOPSIS #include <time.h> int clock_getres(clockid_t clockid, struct timespec *res); int clock_gettime(clockid_t clockid, struct timespec *tp); int clock_settime(clockid_t clockid, const struct timespec *tp); Link with -lrt (only for glibc versions before 2.17). Feature Test Macro Requirements for glibc (see feature_test_macros(7)): clock_getres(), clock_gettime(), clock_settime(): _POSIX_C_SOURCE >= 199309L DESCRIPTION The function…
NAME clock_getres, clock_gettime, clock_settime – clock and time functions SYNOPSIS #include <time.h> int clock_getres(clockid_t clockid, struct timespec *res); int clock_gettime(clockid_t clockid, struct timespec *tp); int clock_settime(clockid_t clockid, const struct timespec *tp); Link with -lrt (only for glibc versions before 2.17). Feature Test Macro Requirements for glibc (see feature_test_macros(7)): clock_getres(), clock_gettime(), clock_settime(): _POSIX_C_SOURCE >= 199309L DESCRIPTION The function…
NAME adjtimex, clock_adjtime, ntp_adjtime – tune kernel clock SYNOPSIS #include <sys/timex.h> int adjtimex(struct timex *buf); int clock_adjtime(clockid_t clk_id, struct timex *buf); int ntp_adjtime(struct timex *buf); DESCRIPTION Linux uses David L. Mills’ clock adjustment algorithm (see RFC 5905). The system call adjtimex() reads and optionally sets adjustment parameters for this algorithm. It takes a pointer to…
NAME chroot – change root directory SYNOPSIS #include <unistd.h> int chroot(const char *path); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): chroot(): Since glibc 2.2.2: _XOPEN_SOURCE && !(_POSIX_C_SOURCE & nbsp; >= 200112L) || /* Since glibc 2.20: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE Before glibc 2.2.2: none DESCRIPTION chroot() changes…
NAME chown, fchown, lchown, fchownat – change ownership of a file SYNOPSIS #include <unistd.h> int chown(const char *pathname, uid_t owner, gid_t group); int fchown(int fd, uid_t owner, gid_t group); int lchown(const char *pathname, uid_t owner, gid_t group); #include <fcntl.h> /* Definition of AT_* constants */ #include <unistd.h> int fchownat(int dirfd, const char *pathname, uid_t owner,…
NAME chown, fchown, lchown, fchownat – change ownership of a file SYNOPSIS #include <unistd.h> int chown(const char *pathname, uid_t owner, gid_t group); int fchown(int fd, uid_t owner, gid_t group); int lchown(const char *pathname, uid_t owner, gid_t group); #include <fcntl.h> /* Definition of AT_* constants */ #include <unistd.h> int fchownat(int dirfd, const char *pathname, uid_t owner,…
NAME chmod, fchmod, fchmodat – change permissions of a file SYNOPSIS #include <sys/stat.h> int chmod(const char *pathname, mode_t mode); int fchmod(int fd, mode_t mode); #include <fcntl.h> /* Definition of AT_* constants */ #include <sys/stat.h> int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): fchmod(): Since glibc…
NAME capget, capset – set/get capabilities of thread(s) SYNOPSIS #include <sys/capability.h> int capget(cap_user_header_t hdrp, cap_user_data_t datap); int capset(cap_user_header_t hdrp, const cap_user_data_t datap); DESCRIPTION These two system calls are the raw kernel interface for getting and setting thread capabilities. Not only are these system calls specific to Linux, but the kernel API is likely to change…
NAME capget, capset – set/get capabilities of thread(s) SYNOPSIS #include <sys/capability.h> int capget(cap_user_header_t hdrp, cap_user_data_t datap); int capset(cap_user_header_t hdrp, const cap_user_data_t datap); DESCRIPTION These two system calls are the raw kernel interface for getting and setting thread capabilities. Not only are these system calls specific to Linux, but the kernel API is likely to change…
NAME cacheflush – flush contents of instruction and/or data cache SYNOPSIS #include <asm/cachectl.h> int cacheflush(char *addr, int nbytes, int cache); Note: On some architectures, there is no glibc wrapper for this system call; see NOTES. DESCRIPTION cacheflush() flushes the contents of the indicated cache(s) for the user addresses in the range addr to (addr+nbytes-1). cache…
NAME brk, sbrk – change data segment size SYNOPSIS #include <unistd.h> int brk(void *addr); void *sbrk(intptr_t increment); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): brk(), sbrk(): Since glibc 2.19: _DEFAULT_SOURCE || (_XOPEN_SOURCE & nbsp; >= 500) && !(_POSIX_C_SOURCE & nbsp; >= 200112L) From glibc 2.12 to 2.19: _BSD_SOURCE || _SVID_SOURCE || (_XOPEN_SOURCE…
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…