lowercase.c

[詳解]

/*++
/* NAME
/*  lowercase 3
/* SUMMARY
/*  map uppercase characters to lowercase
/* SYNOPSIS
/*  #include <stringops.h>
/*
/*  char    *lowercase(buf)
/*  char    *buf;
/* DESCRIPTION
/*  lowercase() replaces uppercase characters in its null-terminated
/*  input by their lowercase equivalent.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*--*/

/* System library. */

#include "sys_defs.h"
#include <ctype.h>

/* Utility library. */

#include "stringops.h"

char   *lowercase(char *string)
{
    char   *cp;
    int     ch;

    for (cp = string; (ch = *cp) != 0; cp++)
    if (ISUPPER(ch))
        *cp = TOLOWER(ch);
    return (string);
}