Section 2: system calls
outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p – port I/O Synopsis#include <sys/io.h> unsigned char inb(unsigned short port); unsigned char inb_p(unsigned short port); unsigned short inw(unsigned short port); unsigned short inw_p(unsigned short port); unsigned int inl(unsigned short port); unsigned int inl_p(unsigned short port); void outb(unsigned…
inotify_rm_watch – remove an existing watch from an inotify instance Synopsis#include <sys/inotify.h> int inotify_rm_watch(int fd, int wd); Descriptioninotify_rm_watch() removes the watch associated with the watch descriptor wd from the inotify instance associated with the file descriptor fd. Removing a watch causes an IN_IGNORED event to be generated for this watch descriptor. (See inotify(7).) Return ValueOn…
inotify_init, inotify_init1 – initialize an inotify instance Synopsis#include <sys/inotify.h> int inotify_init(void); int inotify_init1(int flags);DescriptionFor an overview of the inotify API, see inotify(7). inotify_init() initializes a new inotify instance and returns a file descriptor associated with a new inotify event queue. If flags is 0, then inotify_init1() is the same as inotify_init(). The following values can…
inotify_init, inotify_init1 – initialize an inotify instance Synopsis#include <sys/inotify.h> int inotify_init(void); int inotify_init1(int flags);DescriptionFor an overview of the inotify API, see inotify(7). inotify_init() initializes a new inotify instance and returns a file descriptor associated with a new inotify event queue. If flags is 0, then inotify_init1() is the same as inotify_init(). The following values can…
inotify_add_watch – add a watch to an initialized inotify instance Synopsis#include <sys/inotify.h> int inotify_add_watch(int fd, const char *pathname, uint32_t mask); Descriptioninotify_add_watch() adds a new watch, or modifies an existing watch, for the file whose location is specified in pathname; the caller must have read permission for this file. The fd argument is a file descriptor…
outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p – port I/O Synopsis#include <sys/io.h> unsigned char inb(unsigned short port); unsigned char inb_p(unsigned short port); unsigned short inw(unsigned short port); unsigned short inw_p(unsigned short port); unsigned int inl(unsigned short port); unsigned int inl_p(unsigned short port); void outb(unsigned…
outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p – port I/O Synopsis#include <sys/io.h> unsigned char inb(unsigned short port); unsigned char inb_p(unsigned short port); unsigned short inw(unsigned short port); unsigned short inw_p(unsigned short port); unsigned int inl(unsigned short port); unsigned int inl_p(unsigned short port); void outb(unsigned…
init_module, finit_module – load a kernel module Synopsisint init_module(void *module_image, unsigned long len, const char *param_values); int finit_module(int fd, const char *param_values, int flags);Note: glibc provides no header file declaration of init_module() and no wrapper function for finit_module(); see NOTES. Descriptioninit_module() loads an ELF image into kernel space, performs any necessary symbol relocations, initializes module…
outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p – port I/O Synopsis#include <sys/io.h> unsigned char inb(unsigned short port); unsigned char inb_p(unsigned short port); unsigned short inw(unsigned short port); unsigned short inw_p(unsigned short port); unsigned int inl(unsigned short port); unsigned int inl_p(unsigned short port); void outb(unsigned…
outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p – port I/O Synopsis#include <sys/io.h> unsigned char inb(unsigned short port); unsigned char inb_p(unsigned short port); unsigned short inw(unsigned short port); unsigned short inw_p(unsigned short port); unsigned int inl(unsigned short port); unsigned int inl_p(unsigned short port); void outb(unsigned…
idle – make process 0 idle Synopsis#include <unistd.h> int idle(void); Descriptionidle() is an internal system call used during bootstrap. It marks the process’s pages as swappable, lowers its priority, and enters the main scheduling loop. idle() never returns. Only process 0 may call idle(). Any user process, even a process with superuser permission, will receive…
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 SynopsisUnimplemented system calls. DescriptionThese system calls are not implemented in the Linux kernel. Return ValueThese system calls always return -1 and set errno to ENOSYS. NotesNote that ftime(3), profil(3), and…
getxattr, lgetxattr, fgetxattr – retrieve an extended attribute value Synopsis#include <sys/types.h> #include <sys/xattr.h> ssize_t getxattr(const char *path, const char *name, void *value, size_t size); ssize_t lgetxattr(const char *path, const char *name, void *value, size_t size); ssize_t fgetxattr(int fd, const char *name, void *value, size_t size);DescriptionExtended attributes are name:value pairs associated with inodes (files, directories, symbolic links, etc.). They are extensions to the normal…
getunwind – copy the unwind data to caller’s buffer Synopsis#include <syscall.h> #include <linux/unwind.h> long getunwind(void *buf, size_t buf_size);Note: There is no glibc wrapper for this system call; see NOTES. DescriptionNote: this function is obsolete. The IA-64-specific getunwind() system call copies the kernel’s call frame unwind data into the buffer pointed to by buf and returns…
getuid, geteuid – get user identity Synopsis#include <unistd.h> #include <sys/types.h> uid_t getuid(void); uid_t geteuid(void); Descriptiongetuid() returns the real user ID of the calling process. geteuid() returns the effective user ID of the calling process. ErrorsThese functions are always successful. Conforming ToPOSIX.1-2001, POSIX.1-2008, 4.3BSD. NotesHistoryIn UNIX V6 the getuid() call returned (euid << 8) + uid….
getuid, geteuid – get user identity Synopsis#include <unistd.h> #include <sys/types.h> uid_t getuid(void); uid_t geteuid(void); Descriptiongetuid() returns the real user ID of the calling process. geteuid() returns the effective user ID of the calling process. ErrorsThese functions are always successful. Conforming ToPOSIX.1-2001, POSIX.1-2008, 4.3BSD. NotesHistoryIn UNIX V6 the getuid() call returned (euid << 8) + uid….
gettimeofday, settimeofday – get / set time Synopsis#include <sys/time.h> int gettimeofday(struct timeval *tv, struct timezone *tz); int settimeofday(const struct timeval *tv, const struct timezone *tz);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): settimeofday(): Since glibc 2.19: _DEFAULT_SOURCE Glibc 2.19 and earlier: _BSD_SOURCE DescriptionThe functions gettimeofday() and settimeofday() can get and set the time as well…
gettid – get thread identification Synopsis#define _GNU_SOURCE #include <unistd.h> #include <sys/types.h> pid_t gettid(void);Descriptiongettid() returns the caller’s thread ID (TID). In a single-threaded process, the thread ID is equal to the process ID (PID, as returned by getpid(2)). In a multithreaded process, all threads have the same PID, but each one has a unique TID. For…
getsockopt, setsockopt – get and set options on sockets Synopsis#include <sys/types.h> /* See NOTES */ #include <sys/socket.h> int getsockopt(int sockfd, int level, int optname, void *optval, socklen_t *optlen); int setsockopt(int sockfd, int level, int optname, const void *optval, socklen_t optlen);Descriptiongetsockopt() and setsockopt() manipulate options for the socket referred to by the file descriptor sockfd. Options…
getsockname – get socket name Synopsis#include <sys/socket.h> int getsockname(int sockfd, struct sockaddr *addr, socklen_t *addrlen);Descriptiongetsockname() returns the current address to which the socket sockfd is bound, in the buffer pointed to by addr. The addrlen argument should be initialized to indicate the amount of space (in bytes) pointed to by addr. On return it contains…