Advanced Programming in the UNIX® Environment

ptg10805159

Appendix A Function Prototypes 857

char *getenv(const char *name);

<stdlib.h> p. 210

Returns: pointer to value associated withname,

NULLif not found

uid_t geteuid(void);

<unistd.h> p. 228

Returns: effective user ID of calling process

gid_t getgid(void);

<unistd.h> p. 228

Returns: real group ID of calling process

struct

group *getgrent(void);

<grp.h> p. 183

Returns: pointer if OK,NULLon error or end of file

struct

group *getgrgid(gid_tgid);

<grp.h> p. 182

Returns: pointer if OK,NULLon error

struct

group *getgrnam(const char *name);

<grp.h> p. 182

Returns: pointer if OK,NULLon error

int getgroups(intgidsetsize,gid_tgrouplist[]);

<unistd.h> p. 184

Returns: number of supplementary group IDs if OK,

−1 on error

struct

hostent *gethostent(void);

<netdb.h> p. 597

Returns: pointer if OK,NULLon error

int gethostname(char *name,intnamelen);

<unistd.h> p. 188

Returns: 0 if OK,−1 on error

char *getlogin(void);

<unistd.h> p. 275

Returns: pointer to string giving login name if OK,

NULLon error