misc.3

牛顿插值方法求解多项式的系数

.\"(c) Copyright 1992 by Panagiotis Tsirigotis
.\"All rights reserved.  The file named COPYRIGHT specifies the terms 
.\"and conditions for redistribution.
.\"
.\" $Id: misc.3,v 1.1.1.1 2003/02/19 17:29:27 bbraun Exp $
.TH MISC 3X "25 January 1992"
.SH NAME
make_string, make_pathname, argv_copy_and_clear, basename, dirname - miscellaneous functions
.SH SYNOPSIS
.LP
.nf
.ft B
#include "misc.h"
.LP
.ft B
char *make_string( count, ... )
unsigned count ;
.LP
.ft B
char *make_pathname( count, ... )
unsigned count ;
.LP
.ft B
char **argv_copy_and_clear( argv, start, count )
char **argv ;
int start, count ;
.LP
.ft B
char *dirname( path )
char *path ;
.LP
.ft B
char *basename( path )
char *path ;
.SH DESCRIPTION
.LP
This library contain miscellaneous functions, hence the name.
.LP
.B make_string()
creates a string by catenating the list of strings passed as arguments.
\fIcount\fR indicates how many strings there are.
Strings that are
.SM NULL
pointers are ignored.
\fBmake_string()\fR returns malloc'ed memory.
.LP
.B make_pathname()
creates a pathname by catenating the list of pathname components passed
as arguments and inserting slashes between them.
\fIcount\fR indicates how many components there are.
\fBmake_pathname()\fR returns malloc'ed memory.
.LP
.B argv_copy_and_clear()
creates a new argv array of size \fIcount\fR, and fills it with the
contents of \fIargv\fR from \fIstart\fR up to \fIstart+count-1\fR.
The original \fIargv\fR entries in that range are cleared by filling
them with
.SM SPACEs.
.LP
.B dirname()
returns in a malloced string containing all but the last of 
component of \fIpath\fR. There are 2 special cases:
first when the
\fIpath\fR is "/", \fBdirname()\fR will return "/", 
and second, when the \fIpath\fR does not contain any '/',
\fBdirname()\fR will return ".".
.LP
.B basename()
returns a pointer to the last component of \fIpath\fR.
.SH "RETURN VALUES"
.LP
\fBmake_string()\fR returns a pointer to the new string.
It returns
.SM NULL
if \fIcount\fR is 0.
.LP
\fBmake_pathname()\fR returns a pointer to the new pathname.
It returns
.SM NULL
if \fIcount\fR is 0.
.LP
\fBargv_copy_and_clear()\fR returns the new argv array. It returns
.SM NULL
if \fImalloc\fR fails to allocate more memory.
.LP
\fBdirname()\fR returns a new string or
.SM NULL
if \fImalloc\fR fails to allocate more memory.
.LP
\fBbasename()\fR returns a pointer to the last component of \fIpath\fR.
.SH BUGS
.LP
The behavior of \fBdirname()\fR and \fBbasename()\fR is undefined if
they are given a zero-length string.