Linux Manuals session 3

getmntent, setmntent, addmntent, endmntent, hasmntopt, getmntent_r – get filesystem descriptor file entry Synopsis#include <stdio.h> #include <mntent.h> FILE *setmntent(const char *filename, const char *type); struct mntent *getmntent(FILE *stream); int addmntent(FILE *stream, const struct mntent *mnt); int endmntent(FILE *streamp); char *hasmntopt(const struct mntent *mnt, const char *opt); /* GNU extension */ #include <mntent.h> struct mntent *getmntent_r(FILE *streamp,…

getmntent, setmntent, addmntent, endmntent, hasmntopt, getmntent_r – get filesystem descriptor file entry Synopsis#include <stdio.h> #include <mntent.h> FILE *setmntent(const char *filename, const char *type); struct mntent *getmntent(FILE *stream); int addmntent(FILE *stream, const struct mntent *mnt); int endmntent(FILE *streamp); char *hasmntopt(const struct mntent *mnt, const char *opt); /* GNU extension */ #include <mntent.h> struct mntent *getmntent_r(FILE *streamp,…

getlogin, getlogin_r, cuserid – get username Synopsis#include <unistd.h> char *getlogin(void); int getlogin_r(char *buf, size_t bufsize); #include <stdio.h> char *cuserid(char *string); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): getlogin_r(): _POSIX_C_SOURCE >= 199506L cuserid(): Since glibc 2.24: (_XOPEN_SOURCE && ! (_POSIX_C_SOURCE >= 200112L) || _GNU_SOURCE Up to and including glibc 2.23: _XOPEN_SOURCEDescriptiongetlogin() returns a pointer to a string…

getlogin, getlogin_r, cuserid – get username Synopsis#include <unistd.h> char *getlogin(void); int getlogin_r(char *buf, size_t bufsize); #include <stdio.h> char *cuserid(char *string); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): getlogin_r(): _POSIX_C_SOURCE >= 199506L cuserid(): Since glibc 2.24: (_XOPEN_SOURCE && ! (_POSIX_C_SOURCE >= 200112L) || _GNU_SOURCE Up to and including glibc 2.23: _XOPEN_SOURCEDescriptiongetlogin() returns a pointer to a string…

getloadavg – get system load averages Synopsis#include <stdlib.h> int getloadavg(double loadavg[], int nelem);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): getloadavg(): Since glibc 2.19: _DEFAULT_SOURCE In glibc up to and including 2.19: _BSD_SOURCEDescriptionThe getloadavg() function returns the number of processes in the system run queue averaged over various periods of time. Up to nelem samples…

getline, getdelim – delimited string input Synopsis#include <stdio.h> ssize_t getline(char **lineptr, size_t *n, FILE *stream); ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): getline(), getdelim(): Since glibc 2.10: _POSIX_C_SOURCE >= 200809L Before glibc 2.10: _GNU_SOURCEDescriptiongetline() reads an entire line from stream, storing the address of the buffer containing the…

getkeycreatecon, setkeycreatecon – get or set the SELinux security context used for creating a new kernel keyrings Synopsis#include <selinux/selinux.h> int getkeycreatecon(char **con); int getkeycreatecon_raw(char **con); int setkeycreatecon(char *context); int setkeycreatecon_raw(char *context); Descriptiongetkeycreatecon() retrieves the context used for creating a new kernel keyring. This returned context should be freed with freecon(3) if non-NULL. getkeycreatecon() sets *con…

getkeycreatecon, setkeycreatecon – get or set the SELinux security context used for creating a new kernel keyrings Synopsis#include <selinux/selinux.h> int getkeycreatecon(char **con); int getkeycreatecon_raw(char **con); int setkeycreatecon(char *context); int setkeycreatecon_raw(char *context); Descriptiongetkeycreatecon() retrieves the context used for creating a new kernel keyring. This returned context should be freed with freecon(3) if non-NULL. getkeycreatecon() sets *con…

getipnodebyname, getipnodebyaddr, freehostent – get network hostnames and addresses Synopsis#include <sys/types.h> #include <sys/socket.h> #include <netdb.h> struct hostent *getipnodebyname(const char *name, int af, int flags, int *error_num); struct hostent *getipnodebyaddr(const void *addr, size_t len, int af, int *error_num); void freehostent(struct hostent *ip);DescriptionThese functions are deprecated (and unavailable in glibc). Use getaddrinfo(3) and getnameinfo(3) instead. The getipnodebyname()…

getipnodebyname, getipnodebyaddr, freehostent – get network hostnames and addresses Synopsis#include <sys/types.h> #include <sys/socket.h> #include <netdb.h> struct hostent *getipnodebyname(const char *name, int af, int flags, int *error_num); struct hostent *getipnodebyaddr(const void *addr, size_t len, int af, int *error_num); void freehostent(struct hostent *ip);DescriptionThese functions are deprecated (and unavailable in glibc). Use getaddrinfo(3) and getnameinfo(3) instead. The getipnodebyname()…

getifaddrs, freeifaddrs – get interface addresses Synopsis#include <sys/types.h> #include <ifaddrs.h> int getifaddrs(struct ifaddrs **ifap); void freeifaddrs(struct ifaddrs *ifa);DescriptionThe getifaddrs() function creates a linked list of structures describing the network interfaces of the local system, and stores the address of the first item of the list in *ifap. The list consists of ifaddrs structures, defined as…

gethostid, sethostid – get or set the unique identifier of the current host Synopsis#include <unistd.h> long gethostid(void); int sethostid(long hostid); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): gethostid(): _BSD_SOURCE || _XOPEN_SOURCE >= 500 sethostid(): Since glibc 2.21: _DEFAULT_SOURCE In glibc 2.19 and 2.20: _DEFAULT_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500) Up to and including glibc 2.19: _BSD_SOURCE ||…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…

gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, gethostbyname_r, gethostent_r – get network host entry Synopsis#include <netdb.h> extern int h_errno; struct hostent *gethostbyname(const char *name); #include <sys/socket.h> /* for AF_INET */ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type); void sethostent(int stayopen); void endhostent(void); void herror(const char *s); const char *hstrerror(int…