---
name: "setservent"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/getservent"
---

# setservent(3)

get service entry

Part of [getservent(3)](/getservent/3.md).

## NAME

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

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <netdb.h>
```

**struct servent \*getservent(void);**

**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**() function reads the next entry from the services database (see [**services**(5)](/services/5.md)) and returns a *servent* structure containing the broken-out fields from the entry. A connection is opened to the database if necessary.

The **getservbyname**() function returns a *servent* structure for the entry from the database that matches the service *name* using protocol *proto*. If *proto* is NULL, any protocol will be matched. A connection is opened to the database if necessary.

The **getservbyport**() function returns a *servent* structure for the entry from the database that matches the port *port* (given in network byte order) using protocol *proto*. If *proto* is NULL, any protocol will be matched. A connection is opened to the database if necessary.

The **setservent**() function opens a connection to the database, and sets the next entry to the first entry. If *stayopen* is nonzero, then the connection to the database will not be closed between calls to one of the **getserv\***() functions.

The **endservent**() function closes the connection to the database.

The *servent* structure is defined in *\<netdb.h\>* as follows:

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

The members of the *servent* structure are:

- *s\_name*

  The official name of the service.

- *s\_aliases*

  A NULL-terminated list of alternative names for the service.

- *s\_port*

  The port number for the service given in network byte order.

- *s\_proto*

  The name of the protocol to use with this service.

## RETURN VALUE

The **getservent**(), **getservbyname**(), and **getservbyport**() functions return a pointer to a statically allocated *servent* structure, or NULL if an error occurs or the end of the file is reached.

## FILES

- */etc/services*

  services database file

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **getservent**() | Thread safety | MT-Unsafe race:servent race:serventbuf locale |
| **getservbyname**() | Thread safety | MT-Unsafe race:servbyname locale |
| **getservbyport**() | Thread safety | MT-Unsafe race:servbyport locale |
| **setservent**(), **endservent**() | Thread safety | MT-Unsafe race:servent locale |

In the above table, *servent* in *race:servent* signifies that if any of the functions **setservent**(), **getservent**(), or **endservent**() are used in parallel in different threads of a program, then data races could occur.

## STANDARDS

POSIX.1-2008.

## HISTORY

POSIX.1-2001, 4.3BSD.

## SEE ALSO

[**getnetent**(3)](/getnetent/3.md), [**getprotoent**(3)](/getprotoent/3.md), [**getservent\_r**(3)](/getservent_r/3.md), [**services**(5)](/services/5.md)