strutil.3

牛顿插值方法求解多项式的系数

.\"(c) Copyright 1992, 1993 by Panagiotis Tsirigotis
.\"All rights reserved.  The file named COPYRIGHT specifies the terms 
.\"and conditions for redistribution.
.\"
.\" $Id: strutil.3,v 1.1.1.1 2003/02/19 17:29:27 bbraun Exp $
.TH STRUTIL 3X "30 September 1992"
.SH NAME
str_find, str_casefind, str_fill, str_lower, str_upper -- string utility functions
.SH SYNOPSIS
.LP
.nf
.ft B
#include "str.h"
.LP
.ft B
char *str_find( s1, s2 )
char *s1, *s2 ;
.LP
.ft B
char *str_casefind( s1, s2 )
char *s1, *s2 ;
.LP
.ft B
void str_fill( s, c )
char *s ;
char c ;
.LP
.ft B
char *str_lower( s )
char *s ;
.LP
.ft B
char *str_upper( s )
char *s ;
.SH DESCRIPTION
.B str_find()
returns a pointer to the first instance of string \fIs2\fR in string \fIs1\fR.
If \fIs2\fR is the empty string a pointer to \fIs1\fR is returned.
.LP
.B str_casefind()
performs the same function as
.B str_find()
except that it performs case insensitive character comparisons.
.LP
.B str_fill()
fills the string \fIs\fR with the character \fIc\fR.
.LP
.B str_lower()
and
.B str_upper()
convert their argument in place to a lower or upper case string respectively.
.SH "RETURN VALUES"
.LP
\fBstr_find()\fR 
and
.B str_casefind()
return a pointer to the first occurrence of \fIs2\fR
in \fIs1\fR or
.SM NULL
if \fIs2\fR does not exist in \fIs1\fR.
.LP
\fBstr_lower()\fR and \fBstr_upper()\fR return \fIs\fR.