Mac Developer Library Developer
Search

 

This manual page is part of Xcode Tools version 5.0

To obtain these tools:

If you are running a version of Xcode Tools other than 5.0, view the documentation locally:

  • In Xcode

  • In Terminal, using the man(1) command

Reading manual pages

Manual pages are intended as a quick reference for people who already understand a technology.

  • To learn how the manual is organized or to learn about command syntax, read the manual page for manpages(5).

  • For more information about this technology, look for other documentation in the Apple Developer Library.

  • For general information about writing shell scripts, read Shell Scripting Primer.




GETSERVENT(3)            BSD Library Functions Manual            GETSERVENT(3)

NAME
     getservent, getservbyport, getservbyname, setservent, endservent -- get service entry

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <netdb.h>

     struct servent *
     getservent();

     struct servent *
     getservbyname(const char *name, const char *proto);

     struct servent *
     getservbyport(int port, const char *proto);

     void
     setservent(int stayopen);

     void
     endservent(void);

DESCRIPTION
     The getservent(), getservbyname(), and getservbyport() functions each return a pointer to an object
     with the following structure containing the broken-out fields of a line in the network services data
     base, /etc/services.

           struct  servent {
                   char    *s_name;        /* official name of service */
                   char    **s_aliases;    /* alias list */
                   int     s_port;         /* port service resides at */
                   char    *s_proto;       /* protocol to use */
           };

     The members of this structure are:

     s_name     The official name of the service.

     s_aliases  A zero terminated list of alternate names for the service.

     s_port     The port number at which the service resides.  Port numbers are returned in network byte
                order.

     s_proto    The name of the protocol to use when contacting the service.

     The getservent() function reads the next line of the file, opening the file if necessary.

     The setservent() function opens and rewinds the file.  If the stayopen flag is non-zero, the net data
     base will not be closed after each call to getservbyname() or getservbyport().

     The endservent() function closes the file.

     The getservbyname() and getservbyport() functions sequentially search from the beginning of the file
     until a matching protocol name or port number (which must be specified in network byte order) is found,
     or until EOF is encountered.  If a protocol name is also supplied (non- NULL), searches must also match
     the protocol.

FILES
     /etc/services

DIAGNOSTICS
     Null pointer (0) returned on EOF or error.

SEE ALSO
     getprotoent(3), services(5)

HISTORY
     The getservent(), getservbyport(), getservbyname(), setservent(), and endservent() functions appeared
     in 4.2BSD.

BUGS
     These functions use a thread-specific data storage; if the data is needed for future use, it should be
     copied before any subsequent calls overwrite it.  Expecting port numbers to fit in a 32 bit quantity is
     probably naive.

BSD                              July 9, 1995                              BSD

Reporting Problems

The way to report a problem with this manual page depends on the type of problem:

Content errors
Report errors in the content of this documentation with the feedback links below.
Bug reports
Report bugs in the functionality of the described tool or API through Bug Reporter.
Formatting problems
Report formatting mistakes in the online version of these pages with the feedback links below.

Feedback