safe_sprintf.c

ncurses 库 可能有用酒用 没用就算了 我觉得还可以用

/****************************************************************************
 * Copyright (c) 1998-2001,2003 Free Software Foundation, Inc.              *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
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 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Thomas E. Dickey <[e-mail]> 1997                        *
 ****************************************************************************/

#include <curses.priv.h>
#include <ctype.h>

MODULE_ID("$Id: safe_sprintf.c,v 1.18 2003/08/09 21:52:04 tom Exp $")

#if USE_SAFE_SPRINTF

typedef enum {
    Flags, Width, Prec, Type, Format
} PRINTF;

#define VA_INTGR(type) ival = va_arg(ap, type)
#define VA_FLOAT(type) fval = va_arg(ap, type)
#define VA_POINT(type) pval = (void *)va_arg(ap, type)

/*
 * Scan a variable-argument list for printf to determine the number of
 * characters that would be emitted.
 */
static int
_nc_printf_length(const char *fmt, va_list ap)
{
    size_t length = BUFSIZ;
    char *buffer;
    char *format;
    int len = 0;
    size_t fmt_len;
    char fmt_arg[BUFSIZ];

    if (fmt == 0 || *fmt == '\0')
	return 0;
    fmt_len = strlen(fmt) + 1;
    if ((format = typeMalloc(char, fmt_len)) == 0)
	  return -1;
    if ((buffer = typeMalloc(char, length)) == 0) {
	free(format);
	return -1;
    }

    while (*fmt != '\0') {
	if (*fmt == '%') {
	    static char dummy[] = "";
	    PRINTF state = Flags;
	    char *pval = dummy;	/* avoid const-cast */
	    double fval = 0.0;
	    int done = FALSE;
	    int ival = 0;
	    int prec = -1;
	    int type = 0;
	    int used = 0;
	    int width = -1;
	    size_t f = 0;

	    format[f++] = *fmt;
	    while (*++fmt != '\0' && len >= 0 && !done) {
		format[f++] = *fmt;

		if (isdigit(UChar(*fmt))) {
		    int num = *fmt - '0';
		    if (state == Flags && num != 0)
			state = Width;
		    if (state == Width) {
			if (width < 0)
			    width = 0;
			width = (width * 10) + num;
		    } else if (state == Prec) {
			if (prec < 0)
			    prec = 0;
			prec = (prec * 10) + num;
		    }
		} else if (*fmt == '*') {
		    VA_INTGR(int);
		    if (state == Flags)
			state = Width;
		    if (state == Width) {
			width = ival;
		    } else if (state == Prec) {
			prec = ival;
		    }
		    sprintf(fmt_arg, "%d", ival);
		    fmt_len += strlen(fmt_arg);
		    if ((format = realloc(format, fmt_len)) == 0) {
			return -1;
		    }
		    strcpy(&format[--f], fmt_arg);
		    f = strlen(format);
		} else if (isalpha(UChar(*fmt))) {
		    done = TRUE;
		    switch (*fmt) {
		    case 'Z':	/* FALLTHRU */
		    case 'h':	/* FALLTHRU */
		    case 'l':	/* FALLTHRU */
			done = FALSE;
			type = *fmt;
			break;
		    case 'i':	/* FALLTHRU */
		    case 'd':	/* FALLTHRU */
		    case 'u':	/* FALLTHRU */
		    case 'x':	/* FALLTHRU */
		    case 'X':	/* FALLTHRU */
			if (type == 'l')
			    VA_INTGR(long);
			else if (type == 'Z')
			    VA_INTGR(size_t);
			else
			    VA_INTGR(int);
			used = 'i';
			break;
		    case 'f':	/* FALLTHRU */
		    case 'e':	/* FALLTHRU */
		    case 'E':	/* FALLTHRU */
		    case 'g':	/* FALLTHRU */
		    case 'G':	/* FALLTHRU */
			VA_FLOAT(double);
			used = 'f';
			break;
		    case 'c':
			VA_INTGR(int);
			used = 'i';
			break;
		    case 's':
			VA_POINT(char *);
			if (prec < 0)
			    prec = strlen(pval);
			if (prec > (int) length) {
			    length = length + prec;
			    buffer = typeRealloc(char, length, buffer);
			    if (buffer == 0) {
				free(format);
				return -1;
			    }
			}
			used = 'p';
			break;
		    case 'p':
			VA_POINT(void *);
			used = 'p';
			break;
		    case 'n':
			VA_POINT(int *);
			used = 0;
			break;
		    default:
			break;
		    }
		} else if (*fmt == '.') {
		    state = Prec;
		} else if (*fmt == '%') {
		    done = TRUE;
		    used = 'p';
		}
	    }
	    format[f] = '\0';
	    switch (used) {
	    case 'i':
		sprintf(buffer, format, ival);
		break;
	    case 'f':
		sprintf(buffer, format, fval);
		break;
	    default:
		sprintf(buffer, format, pval);
		break;
	    }
	    len += (int) strlen(buffer);
	} else {
	    fmt++;
	    len++;
	}
    }

    free(buffer);
    free(format);
    return len;
}
#endif

/*
 * Wrapper for vsprintf that allocates a buffer big enough to hold the result.
 */
NCURSES_EXPORT(char *)
_nc_printf_string(const char *fmt, va_list ap)
{
    static char *buf;
    static size_t used;
    char *result = 0;

    if (fmt != 0) {
#if USE_SAFE_SPRINTF
	int len = _nc_printf_length(fmt, ap);

	if ((int) used < len + 1) {
	    used = 2 * (len + 1);
	    buf = typeRealloc(char, used, buf);
	}
	if (buf != 0) {
	    *buf = '\0';
	    if (len >= 0) {
		vsprintf(buf, fmt, ap);
	    }
	    result = buf;
	}
#else
	static int rows, cols;

	if (screen_lines > rows || screen_columns > cols) {
	    if (screen_lines > rows)
		rows = screen_lines;
	    if (screen_columns > cols)
		cols = screen_columns;
	    used = (rows * (cols + 1)) + 1;
	    buf = typeRealloc(char, used, buf);
	}

	if (buf != 0) {
# if HAVE_VSNPRINTF
	    vsnprintf(buf, used, fmt, ap);	/* GNU extension */
# else
	    vsprintf(buf, fmt, ap);	/* ANSI */
# endif
	    result = buf;
	}
#endif
    } else if (buf != 0) {	/* see _nc_freeall() */
	free(buf);
	buf = 0;
	used = 0;
    }
    return result;
}