sprintf.c

UNIX下SH的实现源码

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if !defined(BUILTIN) && !defined(SHELL)
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */
#endif

#ifndef lint
static char sccsid[] = "@(#)printf.c	8.1 (Berkeley) 7/20/93";
#endif /* not lint */

#include <sys/types.h>

#include <errno.h>
#include <limits.h>
#include <stdio.h>

#include "bashansi.h"
#include "shell.h"
#include "builtins.h"
#include "stdc.h"

#if !defined (errno)
extern int errno;
#endif

static char	sbuf[1024];
static int	sblen;

/* Gee, I wish sprintf could be reliably counted upon to return the
   number of characters written :-( */
#define PF(f, func) \
do { \
	if (fieldwidth) \
		if (precision) \
			sprintf(sbuf, f, fieldwidth, precision, func); \
		else \
			sprintf(sbuf, f, fieldwidth, func); \
	else if (precision) \
		sprintf(sbuf, f, precision, func); \
	else \
		sprintf(sbuf, f, func); \
	spaddstr (sbuf, strlen (sbuf)); \
} while (0)

static int	 asciicode __P((void));
static void	 escape __P((char *));
static int	 getchr __P((void));
static double	 getdouble __P((void));
static int	 getint __P((int *));
static int	 getlong __P((long *));
static char	*getstr __P((void));
static char	*mklong __P((char *, int));
static void	 usage __P((void));

static char **gargv;

static char *outstr;
static int outsize;
static int outind;

int sprintf_builtin ();
static int sprintf_main ();
static void spaddstr ();

extern char *this_command_name;
extern char *single_quote ();
extern char **make_builtin_argv ();

static char *sprintf_doc[] = {
  "sprintf formats and outputs its arguments, after the second, under control",
  "of the format and assigns the result to the variable named by its first",
  "argument. The format is a character string which contains three types",
  "of objects: plain characters, which are simply copied to the output string,",
  "character escape sequences which are converted and copied to the output",
  "string, and format specifications, each of which causes printing of the",
  "next successive argument.  In addition to the standard sprintf(3) formats,",
  "%b means to expand escapes in the corresponding argument, and %q means",
  "to quote the argument in a way that can be reused as shell input.  Each",
  "one of the format specifications must not expand to more than 1024",
  "characters, though there is no limit on the total size of the output",
  "string.",
  (char *)NULL
};

struct builtin sprintf_struct = {
	"sprintf",
	sprintf_builtin,
	BUILTIN_ENABLED,
	sprintf_doc,
	"sprintf var format [arguments]",
	(char *)0
};

int
sprintf_builtin (list)
     WORD_LIST *list;
{
  int c, r;
  char **v, *varname;
  WORD_LIST *l;
  SHELL_VAR *var;

  if (list == 0)
    {
      builtin_usage ();
      return (EXECUTION_FAILURE);
    }

  varname = list->word->word;
  list = list->next;

  if (legal_identifier (varname) == 0)
    {
      builtin_error ("%s: not a legal variable name", varname);
      return (EXECUTION_FAILURE);
    }

  outind = 0;
  if (outstr == 0)
    outstr = xmalloc (outsize = 64);
  outstr[0] = '\0';

  v = make_builtin_argv (list, &c);
  r = sprintf_main (c, v);
  free (v);

  var = bind_variable (varname, outstr);
  if (readonly_p (var))
    {
      builtin_error ("%s: readonly variable", varname);
      return (EXECUTION_FAILURE);
    }

  return r;
}

static void
spaddstr(str, len)
     char *str;
     int len;
{
  RESIZE_MALLOCED_BUFFER (outstr, outind, len, outsize, 64);
  strcpy (outstr + outind, str);
  outind += len;
}

static int
sprintf_main(argc, argv)
	int argc;
	char *argv[];
{
	extern int optind;
	static char *skip1, *skip2;
	int ch, end, fieldwidth, precision;
	char convch, nextch, *format, *fmt, *start;

	while ((ch = getopt(argc, argv, "")) != EOF)
		switch (ch) {
		case '?':
		default:
			usage();
			return (1);
		}
	argc -= optind;
	argv += optind;

	if (argc < 1) {
		usage();
		return (1);
	}

	/*
	 * Basic algorithm is to scan the format string for conversion
	 * specifications -- once one is found, find out if the field
	 * width or precision is a '*'; if it is, gather up value.  Note,
	 * format strings are reused as necessary to use up the provided
	 * arguments, arguments of zero/null string are provided to use
	 * up the format string.
	 */
	skip1 = "#-+ 0";
	skip2 = "*0123456789";

	escape(fmt = format = *argv);		/* backslash interpretation */
	gargv = ++argv;
	for (;;) {
		end = 0;
		/* find next format specification */
next:		for (start = fmt;; ++fmt) {
			if (!*fmt) {
				/* avoid infinite loop */
				if (end == 1) {
					warnx("missing format character",
					    NULL, NULL);
					return (1);
				}
				end = 1;
				if (fmt > start)
					(void)printf("%s", start);
				if (!*gargv)
					return (0);
				fmt = format;
				goto next;
			}
			/* %% prints a % */
			if (*fmt == '%') {
				if (*++fmt != '%')
					break;
				*fmt++ = '\0';
				(void)printf("%s", start);
				goto next;
			}
		}

		/* skip to field width */
		for (; strchr(skip1, *fmt); ++fmt);
		if (*fmt == '*') {
			if (getint(&fieldwidth))
				return (1);
		} else
			fieldwidth = 0;

		/* skip to possible '.', get following precision */
		for (; strchr(skip2, *fmt); ++fmt);
		if (*fmt == '.')
			++fmt;
		if (*fmt == '*') {
			if (getint(&precision))
				return (1);
		} else
			precision = 0;

		/* skip to conversion char */
		for (; strchr(skip2, *fmt); ++fmt);
		if (!*fmt) {
			warnx("missing format character", NULL, NULL);
			return (1);
		}

		convch = *fmt;
		nextch = *++fmt;
		*fmt = '\0';
		switch(convch) {
		case 'c': {
			char p;

			p = getchr();
			PF(start, p);
			break;
		}
		case 's': {
			char *p;

			p = getstr();
			PF(start, p);
			break;
		}
		case 'b': {		/* expand escapes in argument */
			char *p;

			p = getstr();
			escape(p);
			PF("%s", p);
			break;
		}
		case 'q': {		/* print with shell single quoting */
			char *p, *p2;

			p = getstr();
			p2 = single_quote(p);
			PF("%s", p2);
			free(p2);
			break;
		}
		case 'd': case 'i': case 'o': case 'u': case 'x': case 'X': {
			long p;
			char *f;
			
			if ((f = mklong(start, convch)) == NULL)
				return (1);
			if (getlong(&p))
				return (1);
			PF(f, p);
			break;
		}
		case 'e': case 'E': case 'f': case 'g': case 'G': {
			double p;

			p = getdouble();
			PF(start, p);
			break;
		}
		default:
			warnx("illegal format character", NULL, NULL);
			return (1);
		}
		*fmt = nextch;
	}
	/* NOTREACHED */
}

static char *
mklong(str, ch)
	char *str;
	int ch;
{
	static char copy[64];
	int len;

	len = strlen(str) + 2;
	memmove(copy, str, len - 3);
	copy[len - 3] = 'l';
	copy[len - 2] = ch;
	copy[len - 1] = '\0';
	return (copy);
}

static void
escape(fmt)
	register char *fmt;
{
	register char *store;
	register int value, c;

	for (store = fmt; c = *fmt; ++fmt, ++store) {
		if (c != '\\') {
			*store = c;
			continue;
		}
		switch (*++fmt) {
		case '\0':		/* EOS, user error */
			*store = '\\';
			*++store = '\0';
			return;
		case '\\':		/* backslash */
		case '\'':		/* single quote */
			*store = *fmt;
			break;
		case 'a':		/* bell/alert */
			*store = '\7';
			break;
		case 'b':		/* backspace */
			*store = '\b';
			break;
		case 'c':
			return;
		case 'e':
		case 'E':
			*store = '\033';
			break;
		case 'f':		/* form-feed */
			*store = '\f';
			break;
		case 'n':		/* newline */
			*store = '\n';
			break;
		case 'r':		/* carriage-return */
			*store = '\r';
			break;
		case 't':		/* horizontal tab */
			*store = '\t';
			break;
		case 'v':		/* vertical tab */
			*store = '\13';
			break;
					/* octal constant */
		case '0': case '1': case '2': case '3':
		case '4': case '5': case '6': case '7':
			for (c = 3, value = 0;
			    c-- && *fmt >= '0' && *fmt <= '7'; ++fmt) {
				value <<= 3;
				value += *fmt - '0';
			}
			--fmt;
			*store = value;
			break;
		default:
			*store = *fmt;
			break;
		}
	}
	*store = '\0';
}

static int
getchr()
{
	if (!*gargv)
		return ('\0');
	return ((int)**gargv++);
}

static char *
getstr()
{
	if (!*gargv)
		return ("");
	return (*gargv++);
}

static char *Number = "+-.0123456789";
static int
getint(ip)
	int *ip;
{
	long val;

	if (getlong(&val))
		return (1);
	if (val > INT_MAX) {
		warnx("%s: %s", *gargv, strerror(ERANGE));
		return (1);
	}
	*ip = val;
	return (0);
}

static int
getlong(lp)
	long *lp;
{
	long val;
	char *ep;

	if (!*gargv) {
		*lp = 0;
		return (0);
	}
	if (strchr(Number, **gargv)) {
		errno = 0;
		val = strtol(*gargv, &ep, 0);
		if (*ep != '\0') {
			warnx("%s: illegal number", *gargv, NULL);
			return (1);
		}
		if (errno == ERANGE)
			if (val == LONG_MAX) {
				warnx("%s: %s", *gargv, strerror(ERANGE));
				return (1);
			}
			if (val == LONG_MIN) {
				warnx("%s: %s", *gargv, strerror(ERANGE));
				return (1);
			}
			
		*lp = val;
		++gargv;
		return (0);
	}
	*lp =  (long)asciicode();
	return (0);
}

static double
getdouble()
{
	if (!*gargv)
		return ((double)0);
	if (strchr(Number, **gargv))
		return (atof(*gargv++));
	return ((double)asciicode());
}

static int
asciicode()
{
	register int ch;

	ch = **gargv;
	if (ch == '\'' || ch == '"')
		ch = (*gargv)[1];
	++gargv;
	return (ch);
}

static void
usage()
{
	(void)fprintf(stderr, "usage: printf format [arg ...]\n");
}