shf.c

一个开放源代码的 AT&T 的 Korn Shell 的复制品, 支持大多数 ksh89 的特性。

		return EOF;

	if (shf->flags & SHF_UNBUF) {
		char cc = c;
		int n;

		if (shf->fd < 0)
			internal_errorf(1, "shf_putchar: no fd");
		if (shf->flags & SHF_ERROR) {
			errno = shf->errno_;
			return EOF;
		}
		while ((n = write(shf->fd, &cc, 1)) != 1)
			if (n < 0) {
				if (errno == EINTR
				    && !(shf->flags & SHF_INTERRUPT))
					continue;
				shf->flags |= SHF_ERROR;
				shf->errno_ = errno;
				return EOF;
			}
	} else {
		/* Flush deals with strings and sticky errors */
		if (shf->wnleft == 0 && shf_emptybuf(shf, EB_GROW) == EOF)
			return EOF;
		shf->wnleft--;
		*shf->wp++ = c;
	}

	return c;
}

/* Write a string.  Returns the length of the string if successful, EOF if
 * the string could not be written.
 */
int
shf_puts(s, shf)
	const char *s;
	struct shf *shf;
{
	if (!s)
		return EOF;

	return shf_write(s, strlen(s), shf);
}

/* Write a buffer.  Returns nbytes if successful, EOF if there is an error. */
int
shf_write(buf, nbytes, shf)
	const char *buf;
	int nbytes;
	struct shf *shf;
{
	int orig_nbytes = nbytes;
	int n;
	int ncopy;

	if (!(shf->flags & SHF_WR))
		internal_errorf(1, "shf_write: flags %x", shf->flags);

	if (nbytes < 0)
		internal_errorf(1, "shf_write: nbytes %d", nbytes);

	/* Don't buffer if buffer is empty and we're writting a large amount. */
	if ((ncopy = shf->wnleft)
	    && (shf->wp != shf->buf || nbytes < shf->wnleft))
	{
		if (ncopy > nbytes)
			ncopy = nbytes;
		memcpy(shf->wp, buf, ncopy);
		nbytes -= ncopy;
		buf += ncopy;
		shf->wp += ncopy;
		shf->wnleft -= ncopy;
	}
	if (nbytes > 0) {
		/* Flush deals with strings and sticky errors */
		if (shf_emptybuf(shf, EB_GROW) == EOF)
			return EOF;
		if (nbytes > shf->wbsize) {
			ncopy = nbytes;
			if (shf->wbsize)
				ncopy -= nbytes % shf->wbsize;
			nbytes -= ncopy;
			while (ncopy > 0) {
				n = write(shf->fd, buf, ncopy);
				if (n < 0) {
					if (errno == EINTR
					    && !(shf->flags & SHF_INTERRUPT))
						continue;
					shf->flags |= SHF_ERROR;
					shf->errno_ = errno;
					shf->wnleft = 0;
					/* Note: fwrite(3S) returns 0 for
					 * errors - this doesn't */
					return EOF;
				}
				buf += n;
				ncopy -= n;
			}
		}
		if (nbytes > 0) {
			memcpy(shf->wp, buf, nbytes);
			shf->wp += nbytes;
			shf->wnleft -= nbytes;
		}
	}

	return orig_nbytes;
}

int
#ifdef HAVE_PROTOTYPES
shf_fprintf(struct shf *shf, const char *fmt, ...)
#else
shf_fprintf(shf, fmt, va_alist)
	struct shf *shf;
	const char *fmt;
	va_dcl
#endif
{
	va_list args;
	int n;

	SH_VA_START(args, fmt);
	n = shf_vfprintf(shf, fmt, args);
	va_end(args);

	return n;
}

int
#ifdef HAVE_PROTOTYPES
shf_snprintf(char *buf, int bsize, const char *fmt, ...)
#else
shf_snprintf(buf, bsize, fmt, va_alist)
	char *buf;
	int bsize;
	const char *fmt;
	va_dcl
#endif
{
	struct shf shf;
	va_list args;
	int n;

	if (!buf || bsize <= 0)
		internal_errorf(1, "shf_snprintf: buf %lx, bsize %d",
			(long) buf, bsize);

	shf_sopen(buf, bsize, SHF_WR, &shf);
	SH_VA_START(args, fmt);
	n = shf_vfprintf(&shf, fmt, args);
	va_end(args);
	shf_sclose(&shf); /* null terminates */
	return n;
}

char *
#ifdef HAVE_PROTOTYPES
shf_smprintf(const char *fmt, ...)
#else
shf_smprintf(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	struct shf shf;
	va_list args;

	shf_sopen((char *) 0, 0, SHF_WR|SHF_DYNAMIC, &shf);
	SH_VA_START(args, fmt);
	shf_vfprintf(&shf, fmt, args);
	va_end(args);
	return shf_sclose(&shf); /* null terminates */
}

#undef FP  			/* if you want floating point stuff */

#define BUF_SIZE	128
#define FPBUF_SIZE	(DMAXEXP+16)/* this must be >
				 *	MAX(DMAXEXP, log10(pow(2, DSIGNIF)))
				 *    + ceil(log10(DMAXEXP)) + 8 (I think).
				 * Since this is hard to express as a
				 * constant, just use a large buffer.
				 */

/*
 *	What kinda of machine we on?  Hopefully the C compiler will optimize
 *  this out...
 *
 *	For shorts, we want sign extend for %d but not for %[oxu] - on 16 bit
 *  machines it don't matter.  Assmumes C compiler has converted shorts to
 *  ints before pushing them.
 */
#define POP_INT(f, s, a) (((f) & FL_LONG) ?				\
				va_arg((a), unsigned long)		\
			    :						\
				(sizeof(int) < sizeof(long) ?		\
					((s) ?				\
						(long) va_arg((a), int)	\
					    :				\
						va_arg((a), unsigned))	\
				    :					\
					va_arg((a), unsigned)))

#define ABIGNUM		32000	/* big numer that will fit in a short */
#define LOG2_10		3.321928094887362347870319429	/* log base 2 of 10 */

#define	FL_HASH		0x001	/* `#' seen */
#define FL_PLUS		0x002	/* `+' seen */
#define FL_RIGHT	0x004	/* `-' seen */
#define FL_BLANK	0x008	/* ` ' seen */
#define FL_SHORT	0x010	/* `h' seen */
#define FL_LONG		0x020	/* `l' seen */
#define FL_ZERO		0x040	/* `0' seen */
#define FL_DOT		0x080	/* '.' seen */
#define FL_UPPER	0x100	/* format character was uppercase */
#define FL_NUMBER	0x200	/* a number was formated %[douxefg] */


#ifdef FP
#include <math.h>

static double
my_ceil(d)
	double	d;
{
	double		i;

	return d - modf(d, &i) + (d < 0 ? -1 : 1);
}
#endif /* FP */

int
shf_vfprintf(shf, fmt, args)
	struct shf *shf;
	const char *fmt;
	va_list args;
{
	char		c, *s;
	int		UNINITIALIZED(tmp);
	int		field, precision;
	int		len;
	int		flags;
	unsigned long	lnum;
					/* %#o produces the longest output */
	char		numbuf[(BITS(long) + 2) / 3 + 1];
	/* this stuff for dealing with the buffer */
	int		nwritten = 0;
#ifdef FP
	/* should be in <math.h>
	 *  extern double frexp();
	 */
	extern char *ecvt();

	double		fpnum;
	int		expo, decpt;
	char		style;
	char		fpbuf[FPBUF_SIZE];
#endif /* FP */

	if (!fmt)
		return 0;

	while ((c = *fmt++)) {
		if (c != '%') {
			shf_putc(c, shf);
			nwritten++;
			continue;
		}
		/*
		 *	This will accept flags/fields in any order - not
		 *  just the order specified in printf(3), but this is
		 *  the way _doprnt() seems to work (on bsd and sysV).
		 *  The only resriction is that the format character must
		 *  come last :-).
		 */
		flags = field = precision = 0;
		for ( ; (c = *fmt++) ; ) {
			switch (c) {
			case '#':
				flags |= FL_HASH;
				continue;

			case '+':
				flags |= FL_PLUS;
				continue;

			case '-':
				flags |= FL_RIGHT;
				continue;

			case ' ':
				flags |= FL_BLANK;
				continue;

			case '0':
				if (!(flags & FL_DOT))
					flags |= FL_ZERO;
				continue;

			case '.':
				flags |= FL_DOT;
				precision = 0;
				continue;

			case '*':
				tmp = va_arg(args, int);
				if (flags & FL_DOT)
					precision = tmp;
				else if ((field = tmp) < 0) {
					field = -field;
					flags |= FL_RIGHT;
				}
				continue;

			case 'l':
				flags |= FL_LONG;
				continue;

			case 'h':
				flags |= FL_SHORT;
				continue;
			}
			if (digit(c)) {
				tmp = c - '0';
				while (c = *fmt++, digit(c))
					tmp = tmp * 10 + c - '0';
				--fmt;
				if (tmp < 0)		/* overflow? */
					tmp = 0;
				if (flags & FL_DOT)
					precision = tmp;
				else
					field = tmp;
				continue;
			}
			break;
		}

		if (precision < 0)
			precision = 0;

		if (!c)		/* nasty format */
			break;

		if (c >= 'A' && c <= 'Z') {
			flags |= FL_UPPER;
			c = c - 'A' + 'a';
		}

		switch (c) {
		case 'p': /* pointer */
			flags &= ~(FL_LONG | FL_SHORT);
			if (sizeof(char *) > sizeof(int))
				flags |= FL_LONG; /* hope it fits.. */
			/* aaahhh... */
		case 'd':
		case 'i':
		case 'o':
		case 'u':
		case 'x':
			flags |= FL_NUMBER;
			s = &numbuf[sizeof(numbuf)];
			lnum = POP_INT(flags, c == 'd', args);
			switch (c) {
			case 'd':
			case 'i':
				if (0 > (long) lnum)
					lnum = - (long) lnum, tmp = 1;
				else
					tmp = 0;
				/* aaahhhh..... */

			case 'u':
				do {
					*--s = lnum % 10 + '0';
					lnum /= 10;
				} while (lnum);

				if (c != 'u') {
					if (tmp)
						*--s = '-';
					else if (flags & FL_PLUS)
						*--s = '+';
					else if (flags & FL_BLANK)
						*--s = ' ';
				}
				break;

			case 'o':
				do {
					*--s = (lnum & 0x7) + '0';
					lnum >>= 3;
				} while (lnum);

				if ((flags & FL_HASH) && *s != '0')
					*--s = '0';
				break;

			case 'p':
			case 'x':
			    {
				const char *digits = (flags & FL_UPPER) ?
						  "0123456789ABCDEF"
						: "0123456789abcdef";
				do {
					*--s = digits[lnum & 0xf];
					lnum >>= 4;
				} while (lnum);

				if (flags & FL_HASH) {
					*--s = (flags & FL_UPPER) ? 'X' : 'x';
					*--s = '0';
				}
			    }
			}
			len = &numbuf[sizeof(numbuf)] - s;
			if (flags & FL_DOT) {
				if (precision > len) {
					field = precision;
					flags |= FL_ZERO;
				} else
					precision = len; /* no loss */
			}
			break;

#ifdef FP
		case 'e':
		case 'g':
		case 'f':
		    {
			char *p;

			/*
			 *	This could proabably be done better,
			 *  but it seems to work.  Note that gcvt()
			 *  is not used, as you cannot tell it to
			 *  not strip the zeros.
			 */
			flags |= FL_NUMBER;
			if (!(flags & FL_DOT))
				precision = 6;	/* default */
			/*
			 *	Assumes doubles are pushed on
			 *  the stack.  If this is not so, then
			 *  FL_LONG/FL_SHORT should be checked.
			 */
			fpnum = va_arg(args, double);
			s = fpbuf;
			style = c;
			/*
			 *  This is the same as
			 *	expo = ceil(log10(fpnum))
			 *  but doesn't need -lm.  This is an
			 *  aproximation as expo is rounded up.
			 */
			(void) frexp(fpnum, &expo);
			expo = my_ceil(expo / LOG2_10);

			if (expo < 0)
				expo = 0;

			p = ecvt(fpnum, precision + 1 + expo,
				 &decpt, &tmp);
			if (c == 'g') {
				if (decpt < -4 || decpt > precision)
					style = 'e';
				else
					style = 'f';
				if (decpt > 0 && (precision -= decpt) < 0)
					precision = 0;
			}
			if (tmp)
				*s++ = '-';
			else if (flags & FL_PLUS)
				*s++ = '+';
			else if (flags & FL_BLANK)
				*s++ = ' ';

			if (style == 'e')
				*s++ = *p++;
			else {
				if (decpt > 0) {
					/* Overflow check - should
					 * never have this problem.
					 */
					if (decpt >
						&fpbuf[sizeof(fpbuf)]
							- s - 8)
						decpt =
						 &fpbuf[sizeof(fpbuf)]
							- s - 8;
					(void) memcpy(s, p, decpt);
					s += decpt;
					p += decpt;
				} else
					*s++ = '0';
			}

			/* print the fraction? */
			if (precision > 0) {
				*s++ = '.';
				/* Overflow check - should
				 * never have this problem.
				 */
				if (precision > &fpbuf[sizeof(fpbuf)]
							- s - 7)
					precision =
						&fpbuf[sizeof(fpbuf)]
						- s - 7;
				for (tmp = decpt;  tmp++ < 0 &&
					    precision > 0 ; precision--)
					*s++ = '0';
				tmp = strlen(p);
				if (precision > tmp)
					precision = tmp;
				/* Overflow check - should
				 * never have this problem.
				 */
				if (precision > &fpbuf[sizeof(fpbuf)]
							- s - 7)
					precision =
						&fpbuf[sizeof(fpbuf)]
						- s - 7;
				(void) memcpy(s, p, precision);
				s += precision;
				/*
				 *	`g' format strips trailing
				 *  zeros after the decimal.
				 */
				if (c == 'g' && !(flags & FL_HASH)) {
					while (*--s == '0')
						;
					if (*s != '.')
						s++;
				}
			} else if (flags & FL_HASH)
				*s++ = '.';

			if (style == 'e') {
				*s++ = (flags & FL_UPPER) ? 'E' : 'e';
				if (--decpt >= 0)
					*s++ = '+';
				else {
					*s++ = '-';
					decpt = -decpt;
				}
				p = &numbuf[sizeof(numbuf)];
				for (tmp = 0; tmp < 2 || decpt ; tmp++) {
					*--p = '0' + decpt % 10;
					decpt /= 10;
				}
				tmp = &numbuf[sizeof(numbuf)] - p;
				(void) memcpy(s, p, tmp);
				s += tmp;
			}

			len = s - fpbuf;
			s = fpbuf;
			precision = len;
			break;
		    }
#endif /* FP */

		case 's':
			if (!(s = va_arg(args, char *)))
				s = "(null %s)";
			len = strlen(s);
			break;

		case 'c':
			flags &= ~FL_DOT;
			numbuf[0] = va_arg(args, int);
			s = numbuf;
			len = 1;
			break;

		case '%':
		default:
			numbuf[0] = c;
			s = numbuf;
			len = 1;
			break;
		}

		/*
		 *	At this point s should point to a string that is
		 *  to be formatted, and len should be the length of the
		 *  string.
		 */
		if (!(flags & FL_DOT) || len < precision)
			precision = len;
		if (field > precision) {
			field -= precision;
			if (!(flags & FL_RIGHT)) {
				field = -field;
				/* skip past sign or 0x when padding with 0 */
				if ((flags & FL_ZERO) && (flags & FL_NUMBER)) {
					if (*s == '+' || *s == '-' || *s ==' ')
					{
						shf_putc(*s, shf);
						s++;
						precision--;
						nwritten++;
					} else if (*s == '0') {
						shf_putc(*s, shf);
						s++;
						nwritten++;
						if (--precision > 0 &&
							(*s | 0x20) == 'x')
						{
							shf_putc(*s, shf);
							s++;
							precision--;
							nwritten++;
						}
					}
					c = '0';
				} else
					c = flags & FL_ZERO ? '0' : ' ';
				if (field < 0) {
					nwritten += -field;
					for ( ; field < 0 ; field++)
						shf_putc(c, shf);
				}
			} else
				c = ' ';
		} else
			field = 0;

		if (precision > 0) {
			nwritten += precision;
			for ( ; precision-- > 0 ; s++)
				shf_putc(*s, shf);
		}
		if (field > 0) {
			nwritten += field;
			for ( ; field > 0 ; --field)
				shf_putc(c, shf);
		}
	}

	return shf_error(shf) ? EOF : nwritten;
}