D Used UNIX System & Library Calls

The tables below give an overview of all used UNIX system & library calls. The second, third and fourth column indicate whether the function is conforming to 4.4BSD, SVID2 and POSIX.1 respectively. All used systems claim to be be POSIX.1 conforming, therefore they support all the POSIX.1 function calls, even if they are not marked as such. Note that some system calls are used in local and distributed IPC, these are not repeated in the distributed IPC table.

More information about the used system & library calls can be obtained via the `man function' command, or see B.3 for additional information.

Name BSD SVID POSIX Purpose

kill send signal to a process

sigaction set up a signal handler with diverse options

sigaddset Adds a signal to asignal set

signal set up a signal handler

sigprocmask examines and changes blocked signals

sigsuspend atomically swap out the signal mask while waiting for a signal

Name BSD SVID POSIX Purpose

close close a file descriptor

dup create a copy of a file descriptor

dup2 create a copy of a file descriptor

mkfifo create a FIFO (named pipe)

open open and possibly create a file or device

pipe create pipe (pair of file descriptors, one for reading, one for writing)

read read from a file descriptor

socketpair create a pair of connected sockets

unlink delete a name and possibly the file it refers to

write write to a file descriptor

Name BSD SVID POSIX Purpose

msgctl diverse message control operations

msgget get a message queue identifier

msgrcv receive a message from a message queue

msgsnd send a message to a message queue

semctl diverse semaphore control operations

semget get a semaphore set identifier

semop semaphore operations

shmat attaches a shared memory region to the data segment of the calling process

shmctl diverse shared memory control operations

shmdt detaches a shared memory region from the calling process's data segment

shmget allocates a shared memory region

Name BSD SVID POSIX Purpose

accept waits for a client to connect

bind register name for a socket

connect establish a connection with a server

gethostbyname get network host entry

gethostname get host name

getservbyname get service entry

inet_addr converts the Internet host address from numbers-and-dots notation into binary data in network byte order

inet_ntoa converts the Internet host address given in network byte order to a string in standard numbers-and-dots notation

listen used by connection-oriented server to indicate that it is willing to receive connections

recv receive a message from a socket (only if in connected state)

recvfrom receive a message from a socket rresvport

send transmit a message to another socket (only if in connected state)

sendto transmit a message to another socket

socket create an endpoint for communication

Name BSD SVID POSIX Purpose

t_accept accept a connect request

t_alloc allocate a library structure

t_bind bind an address to a transport endpoint

t_close close a transport endpoint

t_listen listen for a connect request

t_open establish a transport endpoint

t_rcv receive data or expedited data sent over a connection

t_rcvudata receive a data unit

t_snd send data or expedited data over a connection

t_sndudata send a data unit

Name BSD SVID POSIX Purpose

sleep sleep for specified number of seconds

gettimeofday get system time in seconds and microseconds

time returns the value of time in seconds since 00:00:00 UTC, January 1, 1970

times get process and child process (user and system) time

Name BSD SVID POSIX Purpose

sprintf formatted output in a string

strcat appends a string to another string

strerror return string describing error code

strncmp compare two strings up to n characters

strtol convert a string to a long integer

vsprintf formatted output of a varargs argument list in a string

Name BSD SVID POSIX Purpose

exit exit a process normally

fork create an identical child process

getpid get process identification of current process

getppid get process identification of parent process

waitpid wait for process termination

Name BSD SVID POSIX Purpose

bcopy copy byte strings

bzero write zeros to a byte string

free free dynamically allocated memory

malloc allocate memory dynamically

memcpy copy memory area

memset fill memory with a constant byte

select synchronous I/O multiplexing

sysconf get configuration information at runtime

umask set file creation mask

uname get name and information about current kernel