Common API summary for Linux systems

1. Error handling

-fprintf ()

-Perror ()

2. General-purpose I/O model

-FD = open (pathname, flags, mode)

-Numread = Read (fd, buffer, count)

-Numwritten = Write (fd, buffer, count)

-Status = Close (FD)

-off_t lseek (int fd, off_t offset, int whence): Change file offset

-INT IOCTL (int fd, int request, .../*argp*/)

-int fcntl (int fd, int cmd, ...) : File Control operations

-int dup (int oldfd): Copy the file descriptor, return the new file descriptor, ensure the file descriptor is minimal

-int dup2 (int oldfd, int newfd): Create a copy for OLDFD, numbered NEWFD

-ssize_t pread (int fd, void *buf, size_t count, off_t offset): Read at offset

-ssize_t pwrite (int fd, const void *buf, size_t count, off_t offset): Write at offset

-ssize_t readv (int fd, const struct IOVEC *iov, int iovcnt): Decentralized input

-ssize_t Writev (int fd, const struct IOVEC *iov, int iovcnt): Centralized output

-Int truncate (const char *pathname, off_t length): File truncation

-int ftruncate (int fd, off_t length)

-Int mkstemp (char *template): The last 6 characters of a template must be xxxxxx, such as char template[] = "/tmp/somestringxxxxxx"

-File *tmpfile (void): Create temporary file

3. Process

-pid_t getpid (void): Returns the process number of the calling process

-pid_t getppid (void): Returns the parent process process number

-pid_t fork (void)

-Void exit (int status)

-pid_t Wait (int *status): Wait for the child process resource to be reclaimed

-pid_t waitpid (pid_t pid, int *status, int options)

-Int Execve (const char *pathname, char *const argv[], char *const envp[])

-INT System (const char *command): Execute arbitrary shell command

4. Memory allocation

-void *malloc (size_t size)

-Void free (void *ptr)

-Void *calloc (size_t numitems, size_t size): Used to allocate memory for a set of identical objects

-void *realloc (void *ptr, size_t size): Used to adjust the size of a block of memory previously allocated by the malloc function

-void *alloca (size_t size): Ability to allocate memory on the stack without manual release

5. Time

-time_t time (time_t *TIMEP)

-Char *ctime (const time_t *TIMEP): Returns a string representation, Wed June 8 14:2:32 2011

-struct TM *gmtime (const time_t *TIMEP): corresponds to UTC green Time decomposition

-struct TM *localtime (const time_t *TIMEP): Corresponding system local time decomposition

-Char *asctime (const struct TM *timeptr): output format same as CTime

-size_t strftime (char *outstr, size_t maxsize, const char *format, const struct TM *timeptr)

-Char *currtime (const char *format): connotation strftime formatting the current time by the format parameter

-Char *strptime (const char *STR, const char *format, struct TM *timeptr): Converts a string containing a date and time to a decomposition time

6. File I/O

-Int setvbuf (FILE *stream, char *buf, int mode, size_t size): Control stdio Library using buffered form

-Int fflush (FILE *stream): Flush stdio Buffer

-int Fsync (int fd): Flushes buffered data and all elements associated with open file descriptor fd to disk

-int Fileno (file *stream): Convert a stream pointer to a file descriptor

-FILE *fdopen (int fd, const char *mode)

-INT stat (const char *pathname, struct stat *statbuf): Returns information about the named file

-Int Lstat (const char *pathname, struct stat *statbuf): Returns information about the connection file itself

-int Fstat (int fd, struct stat *statbuf)

-int Access (const CAHR *pathname, int mode): Check the access rights of the file

-mode_t umask (mode_t mask): Sets the Umake value of the process

-int chmod (const char *pathname, mode_t mode): Change the file permissions specified by the pathname parameter

-int Fchmod (int fd, mode_t mode)

7. Catalogs and Links

-Int link (const char *oldpath, const char *newpath): Create a hard link

-Int unlink (const char *pathname): Remove hard Links

-int rename (const char *oldpath, const char *newpath): You can either rename the file or move the file to another directory on the same file system

-Int symlink (const char *filepath, const char *linkpath): Soft connection

-int mkdir (const char *pathname, mode_t mode): Create a new directory

-Int rmdir (const char *pathname)

-int Remove (const char *pathname)

-DIR *opendir (const char *dirpath)

-DIR *fdopendir (int fd)

-struct dirent *readdir (DIR *dirp)

-Void Rewinddir (DIR *dirp)

-Int Closedir (DIR *dirp)

-Int Dirfd (DIR *dirp): Returns the file descriptor associated with the DIRP directory stream

-Int NFTW (const char *dirpath, INT (*func) const char *pathname, const struct STAT *statbuf, int typeflag, struct FIW *ft WBUF), int nopenfd, int flags): recursively traverse directory

-Char *getcwd (char *cwdbuf, size_t size): Gets the current working directory

-Int chdir (const char *pathname): Changes the current working directory

-int Fchdir (int fd)

8. Signal

-Void (*signal (int sig, void (*handler))) (int): Change signal processing

-int Kill (pid_t pid, int sig): Send Signal

-Int raise (int sig): Sends a signal to itself

-int Pause (void): Suspends the process until a signal is interrupted

-Unsigned int sleep (unsigned int seconds)

-Int Timer_create (clockid_t clockid, struct sigevent *evp, timer_t *timerid): Create timer

-Int Timer_settime (timer_t timerid, int flags, const struct ITIMERSPEC *value, struct itimerspec *old_value): Set timer

-Int Timer_gettimer (timer_t timerid, struct itimerspec *curr_value): Gets the current value of the timer

-Int Timer_delete (timer_t timerid)

9. Threads

-Int Pthread_create (pthread_t *thread, const pthread_attr_t *attr, void * (*start) (void *), void *arg): Create thread

-void Pthread_exit (void *retval): terminating thread

-pthread_t pthread_self (void): Get thread ID

-int pthread_equal (pthread_t t1, pthread_t T2): Check if two thread IDs are the same

-int Pthread_join (pthread_t thread, void **retval): Waits for thread to terminate and returns after end

-int Pthread_detach (pthread_t thread): The thread thread tag is in a detached state, and the system automatically cleans up and removes it when it terminates

-Int Pthread_mutex_lock (pthread_mutex_t *mutex): Lock and Unlock Mutex

-Int Pthread_mutex_unlock (pthread_mutex_t *mutex)

10. Inter-process communication

Pipeline

-INT pipe (int filedes[2]): Create nameless pipe

-Int Mkfifo (const char *pathname, mode_t mode): Creating a named pipe

Message Queuing

-int Msgget (key_t key, int msgflg): Create a new message queue or get an identifier for an existing queue

-int msgsnd (int msqid, const void *MSGP, size_t msgsz, int msgflg): Writes a message to Message Queuing

-ssize_t MSGRCV (int msqid, void *msgp, size_t maxmsgz, long Msgtyp, int msgflg): Read and delete messages from Message Queuing

-int Msgctl (int msqid, int cmd, struct msqid_ds *buf): Performs a control operation on the message queue of the identifier Wiemsqid

Signal Volume

-int Semget (key_t key, int nsems, int semflg): Create a new semaphore set

-int Semctl (int semid, int semnum, int cmd, ...) : Performs various control operations on a semaphore set

Shared memory

-int Shmget (key_t key, size_t size, int shmflg): Create a new Shared memory segment or get an identifier for an existing segment

-void *shmat (int shmid, const void *shmaddr, int shmflg): Shared memory segment identified by Shmid

-int SHMDT (const void *SHMADDR): Use SHMDT to detach when no access to shared memory is required

-int Shmctl (int shmid, int cmd, struct shmid_ds *buf)

File mapping

-void *mmap (void *addr, size_t length, int prot, int flags, int fd, off_t offset): Creates a new mapping in the virtual address space of the calling process

-int Munmap (void *addr, size_t length): de-map area

-int Msync (void *addr, size_t length, int flags): Synchronous map Area

11. Network

Streaming sockets

-int socket (int domain, int type, int protocol): Create a socket

-int bind (int sockfd, const struct SOCKADDR *addr, socklen_t Addrlen): Bind socket to address

-int Listen (int sockfd, int backlog): Listen for access connection

-int Accept (int sockfd, struct sockaddr *addr, socklen_t Addrlen): Accept Connection

-int Connect (int sockfd, const struct SOCKADDR *addr, socklen_t Addrlen): Connect to Peer Socket

-int Close (int fd): Connection terminated

Packet sockets

-ssize_t recvfrom (int sockfd, void *buffer, size_t length, int flags, struct sockaddr *src_addr, socklen_t *addrne)

-ssize_t sendto (int sockfd, const void *buffer, size_t length, int flags, const struct SOCKADDR *dest_addr, socklen_t add Rlen)

Common API summary for Linux systems