substr

来自「Calc Software Package for Number Calc」· 代码 · 共 66 行

NAME
    substr - extract a substring of given string

SYNOPSIS
    substr(str, pos, len)

TYPES
    str		string
    pos		nonnegative integer
    len		nonnegative integer

    return	string

DESCRIPTION
    If pos > length of str or len is zero, the null string "" is returned.

    If 1 <= pos <= strlen(str), substr(str, pos, len) returns the
    string of length min(strlen(str) - pos + 1, len) formed by
    consecutive characters of str starting at position pos, i.e. the
    string has length len if this is possible, otherwise it ends with
    the last character of str.	(The first character has pos = 1, the
    second pos = 2, etc.)

    If pos = 0, the result is the same as for pos = 1.

EXAMPLE
    ; A = "abcde";
    ; print substr(A,0,2), substr(A,1,2), substr(A,4,1), substr(A,3,5)
    ab ab d cde

LIMITS
    none

LINK LIBRARY
    none

SEE ALSO
    strcat, strcpy, strerror, strlen, strncmp, strncpy, strpos,
    strprintf, strscan, strscanf

## Copyright (C) 1999-2006  Ernest Bowen
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL.  You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
##
## @(#) $Revision: 29.4 $
## @(#) $Id: substr,v 29.4 2006/06/25 22:16:55 chongo Exp $
## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/substr,v $
##
## Under source code control:	1995/10/05 04:52:27
## File existed as early as:	1995
##
## chongo <was here> /\oo/\	http://www.isthe.com/chongo/
## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/