pinghost.3

ping代码的封装

.\" Copyright 2001 by Jeffrey Fulmer <[e-mail]>
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one
.\" 
.TH PINGHOST 3  "May 18, 2001" "" "libping Programmer's Manual"
.SH NAME
.B pinghost, pingthost
\- issue an ICMP request to a host.\fR
.br
.B tpinghost, tpingthost
\- issue an ICMP request to a host and return the round trip time in milliseconds. 
.SH SYNOPSIS
.nf
.B #include <ping.h>
.sp
.BI "int pinghost(const char *" host " );
.sp
.BI "int pingthost(const char *" host ", int t );
.sp
.BI "int tpinghost(const char *" host " );
.sp
.BI "int tpingthost(const char *" host ", int t ); 
.fi
.SH DESCRIPTION
The \fBpinghost()\fP function issues a icmp echo request to a 
host.  It returns 1 if the host replies, 0 if the ping request
timed out and less than zero on an error (see return values below.)
.PP
The \fBpingthost()\fP function is similar, except it accepts a 
user specified time out value. The default time out value used
by pinghost() is 2 seconds. On slower, less reliable networks
you may want to increase the time out value. (pronounced: ping-tee-host)
.PP
The \fBtpinghost()\fP function issues a icmp echo request to a
host.  On success, it returns the round trip time in milliseconds.
(pronounced: tee-ping-host)
.PP
The \fBtpingthost()\fP function is similar, except it accepts a
user specified time out value. The default time out value used
by pinghost() is 2 seconds. On slower, less reliable networks
you may want to increase the time out value. 
(pronounced: tee-ping-tee-host)
.SH "RETURN VALUE"
The \fBpinghost()\fP, \fBpingthost()\fP, \fBtpinghost()\fP and 
\fBtpingthost()\fP functions all return an integer value.\fP
.br
>1 \-\- Round trip time in milliseconds.\fB
.br
 1 \-\- Host is alive.\fB
.br
 0 \-\- Connection timed out.\fB
.br
\-1 \-\- Host or service is not reachable.\fB
.br
\-2 \-\- Socket error.\fB
.br
\-3 \-\- Connection refused.
.SH "CONFORMING TO"
SVID 3, POSIX, BSD 4.3, ISO 9899
.SH "SEE ALSO"
.BR ding "(1), "  echohost "(3), "  pinghttp "(3), " pingpop3 "(3), "  pingsmtp "(3)"