Advanced Programming in the UNIX® Environment

ptg10805159

Appendix A Function Prototypes 849

unsigned

int CMSG_LEN(unsigned intnbytes);

<sys/socket.h> p. 645

Returns: size to allocate for data objectnbyteslarge

struct

cmsghdr *CMSG_NXTHDR(struct msghdr *mp,struct cmsghdr *cp);

<sys/socket.h> p. 645

Returns: pointer to nextcmsghdrstructureassociated with

themsghdrstructuregiven the currentcmsghdr

structure, orNULLif we’re at the last one

int connect(intsockfd,const struct sockaddr *addr,

socklen_tlen);

<sys/socket.h> p. 605

Returns: 0 if OK,−1 on error

int creat(const char *path,mode_tmode);

<fcntl.h> p. 66

mode:S_IS[UG]ID, S_ISVTX,

S_I[RWX](USR|GRP|OTH)

Returns: file descriptor opened for write-only if OK,

−1 on error

char *ctermid(char *ptr);

<stdio.h> p. 694

Returns: pointer to name of controlling terminal on success,

pointer to empty string on error

int dprintf(intfd,const char *restrictformat,...);

<stdio.h> p. 159

Returns: number of characters output if OK, negative value

if output error

int dup(intfd);

<unistd.h> p. 79

Returns: new file descriptor if OK,−1 on error

int dup2(intfd,intfd2);

<unistd.h> p. 79

Returns: new file descriptor if OK,−1 on error

void endgrent(void);

<grp.h> p. 183

void endhostent(void);

<netdb.h> p. 597