ihost/libukcprog/formf.c

/*  formf.c -- formatted strings and error messages  */

/*  Copyright 1992  Godfrey Paul, University of Kent at Canterbury.
 *
 *  You can do what you like with this source code as long as
 *  you don't try to make money out of it and you include an
 *  unaltered copy of this message (including the copyright).
 */

char ukcprog_formf_sccsid[] = "$Id: formf.c,v 1.25 1999/07/15 11:10:21 djb1 Exp $ UKC";

#ifdef __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#ifndef __STDC__
#include <memory.h>
#endif

#include "ukcprog.h"

#ifndef MSDOS
#ifndef __FreeBSD__
#ifndef linux
extern int sys_nerr, errno;
extern char *sys_errlist[];
#endif /* !linux */
#endif /* !__FreeBSD__ */
#endif /* !MSDOS */


/* forward declarations */
static void new_buffer PROTO((char ** p_buf, int *p_lim, bool *p_from_malloc));
static void concat PROTO((char **p_buf, int *p_pos, int* p_lim,
                                bool *p_from_malloc, const char *str, int len));
static char *long_to_ascii PROTO((unsigned long unum, int base,
                                                bool want_uppercase));
static char *float_to_ascii PROTO((double d, int precision));
static char *efloat_to_ascii PROTO((double d, int precision,
                                                bool want_uppercase));
static char *gfloat_to_ascii PROTO((double d, int precision,
                                                bool want_uppercase));

#define MAX_NUM_LEN     40      /* buffer sizes used in numeric conversions */
#define MAX_FLOAT_LEN   128


/*
 *  new_buffer()
 *  Reallocate the given buffer to twice its current size.  *p_lim is the
 *  last usable character in the buffer.  The buffer passed in might
 *  not have been allocated by malloc(); this is indicated by *p_from_malloc.
 */
static void
new_buffer(p_buf, p_lim, p_from_malloc)
char **p_buf;
int *p_lim;
bool *p_from_malloc;
{
        char *new;
        size_t size;

        size = *p_lim + 1;

        if (*p_from_malloc)
                new = realloc(*p_buf, size * 2);

        else {
                if ((new = malloc(size * 2)) != NULL)
                        memcpy(new, *p_buf, size);
                *p_from_malloc = TRUE;
        }

        if (new == NULL)
                panic("malloc returned NULL in new_buffer");

        *p_buf = new;
        *p_lim = (size * 2) - 1;
}


/*
 *  concat()
 *  Add exactly len bytes of str to the buffer, expanding it with
 *  new_buffer() if we need extra space.  Str must be at least len
 *  bytes long.
 */
static void
concat(p_buf, p_pos, p_lim, p_from_malloc, str, len)
char **p_buf;
int *p_pos, *p_lim;
bool *p_from_malloc;
const char *str;
int len;
{
        while (*p_lim - *p_pos < len)
                new_buffer(p_buf, p_lim, p_from_malloc);

        memcpy(&(*p_buf)[*p_pos], str, (size_t)len);
        *p_pos += len;
}


static char *
long_to_ascii(unum, base, want_uppercase)
unsigned long unum;
int base;
bool want_uppercase;
{
        static char nbuf[MAX_NUM_LEN + 1];
        char *s;
        const char *digs;

        s = nbuf + MAX_NUM_LEN;

        digs = want_uppercase ? "0123456789ABCDEF" : "0123456789abcdef";
        do {
                *--s = digs[unum % base];
                unum /= base;
        } while (unum != 0);


        return s;
}


static char *
float_to_ascii(d, precision)
double d;
int precision;
{
        static char buf[MAX_FLOAT_LEN];

        sprintf(buf, "%.*f", precision, d);
        return buf;
}


static char *
efloat_to_ascii(d, precision, want_uppercase)
double d;
int precision;
bool want_uppercase;
{
        static char buf[MAX_FLOAT_LEN];
        const char *format;

        if (want_uppercase)
                format = "%.*E";
        else
                format = "%.*e";

        sprintf(buf, format, precision, d);
        return buf;
}


static char *
gfloat_to_ascii(d, precision, want_uppercase)
double d;
int precision;
bool want_uppercase;
{
        static char buf[MAX_FLOAT_LEN];
        const char *format;

        if (want_uppercase)
                format = "%.*G";
        else
                format = "%.*g";

        sprintf(buf, format, precision, d);
        return buf;
}

#ifdef VMS
static const char *
vms_error_text(unsigned long msgid)
{
        unsigned long status;
        unsigned short msglen;
        static char buf[256 + 1];
        static struct dsc$descriptor_s msg = {
                sizeof buf - 1,         /* length */
                DSC$K_DTYPE_T,          /* data type (8 bit chars) */
                DSC$K_CLASS_S,          /* class (fixed length) */
                buf
        };

        status = SYS$GETMSG(msgid, &msglen, &msg, 0, 0);
        if (status != SS$_NORMAL && status != SS$_MSGNOTFND)
                sprintf(buf, "Unknown VMS message ID 0x%x", msgid);
        else
                buf[msglen] = '\0';

        return buf;
}
#endif /* VMS */

/*
 *  formf()
 *  Returns a pointer to a string formatted from the arguments given.
 *  If the string has been obtained from malloc(), the return value will
 *  be different to the buffer pased in; it is the caller's responsibility
 *  to free() this when no longer required.
 */
char *
formf(buffer_space, buffer_size, format, args)
char *buffer_space;
int buffer_size;
const char *format;
va_list args;
{
        bool left_justify, print_sign, zero_pad, alternate_form;
        bool is_negative, precision_given, want_uppercase, from_malloc;
        int min_field_width, precision, modifier, base, pos, lim, len;
        const char *fmt, *alternate_prefix, *s;
        char *buf, str[2], errno_buffer[42];
        int alternate_size, saved_errno;
        unsigned long u;
        long i;
        int *ip;
        double d;

        saved_errno = errno;    /* for use later in %m format */

        /*
         *  The formatted string is prepared in a buffer pointed to by buf.
         *  This starts out pointing to a buffer passed in as an argument,
         *  but if this fills, a new one is obtained from malloc().
         *  Pos is the index of the position for the *next* character
         *  in the output string, and lim is the index of the last
         *  usable character.
         */
        from_malloc = FALSE;
        buf = buffer_space;
        lim = buffer_size - 1;
        pos = 0;
        fmt = format;

        for (;;) {
                min_field_width = 0;
                precision_given = FALSE;
                precision = 0;
                modifier = 0;
                left_justify = FALSE;
                print_sign = FALSE;
                zero_pad = FALSE;
                alternate_form = FALSE;

                /*  Find next argument for conversion */
                while (*fmt != '\0' && *fmt != '%') {
                        if (pos == lim)
                                new_buffer(&buf, &lim, &from_malloc);

                        buf[pos++] = *fmt++;
                }

                if (*fmt == '\0') {
                        buf[pos] = '\0';
                        return buf;     /* end of format string */
                }

                /* flags, in any order */
                for (;;) {
                        if (*++fmt == '\0')
                                panic("confused format flags in formf");

                        if (*fmt == '-')
                                left_justify = TRUE;

                        else if (*fmt == '+')
                                print_sign = TRUE;

                        else if (*fmt == '0')
                                zero_pad = TRUE;

                        else if (*fmt == '#')
                                alternate_form = TRUE;
                        
                        else
                                break;  /* end of flags */

                }

                /* minimum field width */
                if (*fmt == '*') {
                        min_field_width = va_arg(args, int);
                        ++fmt;
                } else
                        while (isdigit(*fmt)) {
                                min_field_width *= 10;
                                min_field_width += *fmt - '0';
                                ++fmt;
                        }
                
                if (*fmt == '.') {

                        /* precision */
                        if (*++fmt == '*') {
                                precision_given = TRUE;
                                precision = va_arg(args, int);
                                ++fmt;
                        } else if (isdigit(*fmt)) {
                                precision_given = TRUE;
                                precision = 0;
                                do {
                                        precision *= 10;
                                        precision += *fmt - '0';
                                        ++fmt;
                                } while (isdigit(*fmt));
                        }
                }

                if (strchr("hlL", *fmt) != NULL)
                        modifier = *fmt++;

                want_uppercase = TRUE;
                alternate_prefix = "0X";
                alternate_size = 2;
                is_negative = FALSE;

                switch (*fmt) {
                        case 'd':
                        case 'i':
                                if (modifier == 'h')
                                        i = va_arg(args, short);
                                else if (modifier == 'l')
                                        i = va_arg(args, long);
                                else
                                        i = va_arg(args, int);
                                is_negative = i < 0;
                                u = is_negative ? -i : i;
                                s = long_to_ascii(u, 10, want_uppercase);
                                break;

                        case 'o':
                                base = 8;
                                alternate_prefix = "0";
                                alternate_size = 1;
                                goto gencase;
                        case 'p':
                                alternate_prefix = "0x";
                                alternate_size = 2;
                                want_uppercase = FALSE;
                                base = 16;
                                print_sign = FALSE;
                                u = (unsigned long)va_arg(args, char *);
                                s = long_to_ascii(u, base, want_uppercase);
#ifdef MSDOS
                                /*  The traditional format for pointers on
                                 *  MSDOS is segment:offset.  NOTE: we depend
                                 *  on long_to_ascii() returning a buffer with
                                 *  space before the beginning.
                                 */
                                if ((len = strlen(s)) <= 8) {
                                        s -= 8 - len;
                                        memset(s, '0', 8 - len);

                                        --s;
                                        memmove(s, s + 1, 4);
                                        s[4] = ':';
                                }
#endif
                                break;
                        case 'x':
                                alternate_prefix = "0x";
                                alternate_size = 2;
                                want_uppercase = FALSE;
                                /* fall through */;
                        case 'X':
                                base = 16;
                                goto gencase;
                        case 'u':
                                base = 10;
gencase:                        if (modifier == 'h')
                                        u = va_arg(args, short);
                                else if (modifier == 'l')
                                        u = va_arg(args, long);
                                else
                                        u = va_arg(args, int);
                                s = long_to_ascii(u, base, want_uppercase);
                                break;

                        case 'c':
                                str[0] = (char)va_arg(args, int);  /* promoted char */
                                str[1] = '\0';
                                s = str;
                                print_sign = FALSE;
                                break;

                        case '%':
                                str[0] = '%';
                                str[1] = '\0';
                                s = str;
                                print_sign = FALSE;
                                break;

                        case 's':
                                s = va_arg(args, char *);
                                if (s == NULL)
                                        panic("null pointer for %s in formf");
                                print_sign = FALSE;
                                break;
                        case 'm':
                                if (saved_errno < 0 || saved_errno > sys_nerr ||
                                            *sys_errlist[saved_errno] == '\0') {
                                        sprintf(errno_buffer,
                                                "errno %d out of range",
                                                                saved_errno);
                                        s = errno_buffer;
                                } else
                                        s = sys_errlist[saved_errno];
                                print_sign = FALSE;
                                break;
#ifdef VMS
                        case 'M':
                                s = vms_error_text(va_arg(args, unsigned));
                                print_sign = FALSE;
                                break;
#endif /* VMS */
                        case 'f':
                                d = va_arg(args, double);
                                is_negative = d < 0.0;
                                if (is_negative)
                                        d = -d;
                                if (!precision_given)
                                        precision = 6;  /* from K&R */
                                s = float_to_ascii(d, precision);
                                break;
                        case 'e':
                                want_uppercase = FALSE; /* fall through */
                        case 'E':
                                d = va_arg(args, double);
                                is_negative = d < 0.0;
                                if (is_negative)
                                        d = -d;
                                if (!precision_given)
                                        precision = 6;  /* from K&R */
                                s = efloat_to_ascii(d, precision,
                                                        want_uppercase);
                                break;
                        case 'g':
                                want_uppercase = FALSE; /* fall through */
                        case 'G':
                                d = va_arg(args, double);
                                is_negative = d < 0.0;
                                if (is_negative)
                                        d = -d;
                                if (!precision_given)
                                        precision = 6;  /* from K&R */
                                s = gfloat_to_ascii(d, precision,
                                                        want_uppercase);
                                break;
                        case 'n':
                                ip = va_arg(args, int *);
                                *ip = pos;

                                ++fmt;  /* step over format character */
                                continue;
                        
                        default:
                                panic("illegal format in formf");
                                s = NULL;       /* to satisfy gcc */
                                break;
                }

                len = strlen(s);

                /* truncate strings if requested */
                if ((*fmt == 's' || *fmt == 'm')
                                && precision_given && precision < len)
                        len = precision;

                if (!left_justify) {
                        const char *fillch_str = zero_pad ? "0" : " ";

                        if ((is_negative || print_sign) && zero_pad) {
                                concat(&buf, &pos, &lim, &from_malloc,
                                       is_negative ? "-" : "+", 1);
                                is_negative = print_sign = FALSE;
                                --min_field_width;
                        }

                        if (alternate_form && alternate_prefix != NULL) {
                                concat(&buf, &pos, &lim, &from_malloc,
                                        alternate_prefix, alternate_size);
                                min_field_width -= alternate_size;
                                alternate_form = FALSE;
                        }

                        while (len < min_field_width) {
                                concat(&buf, &pos, &lim, &from_malloc,
                                                                fillch_str, 1);
                                --min_field_width;
                        }
                }

                if (is_negative || print_sign) {
                        concat(&buf, &pos, &lim, &from_malloc,
                               is_negative ? "-" : "+", 1);
                        --min_field_width;
                }

                if (alternate_form && alternate_prefix != NULL) {
                        concat(&buf, &pos, &lim, &from_malloc,
                                        alternate_prefix, alternate_size);
                        min_field_width -= alternate_size;
                }

                
                concat(&buf, &pos, &lim, &from_malloc, s, len);
                min_field_width -= len;

                if (left_justify) {
                        while (min_field_width > 0) {
                                concat(&buf, &pos, &lim, &from_malloc, " ", 1);
                                --min_field_width;
                        }
                }

                ++fmt;  /* step over format character */
        }
}
Revision:	1.1
Committed:	Fri Mar 8 14:37:29 2002 UTC (22 years, 8 months ago) by tdb
Content type:	text/plain
Branch:	MAIN
CVS Tags:	IHOST_1_5_3, IHOST_1_5_2, IHOST_1_5_1, IHOST_1_5, IHOST_1_0_RC1
Log Message:	I'm not usually up for putting third party sources in here, but in this case I'll make an exception. This is ukcprog, a set of useful C functions which the ihost plugins Pete's writing uses. It's got a pretty free license too. I've munged the Makefile around, as all it needs to do now is make the library, not install anything. The idea is to statically compile the other programs against this library, making the final binary independent of this code etc.
#	User	Rev	Content
1	tdb	1.1	/* formf.c -- formatted strings and error messages */
2
3			/* Copyright 1992 Godfrey Paul, University of Kent at Canterbury.
4			*
5			* You can do what you like with this source code as long as
6			* you don't try to make money out of it and you include an
7			* unaltered copy of this message (including the copyright).
8			*/
9
10			char ukcprog_formf_sccsid[] = "$Id: formf.c,v 1.25 1999/07/15 11:10:21 djb1 Exp $ UKC";
11
12			#ifdef __STDC__
13			#include <stdarg.h>
14			#else
15			#include <varargs.h>
16			#endif
17
18			#include <stdio.h>
19			#include <ctype.h>
20			#include <errno.h>
21			#include <stdlib.h>
22			#include <string.h>
23			#ifndef __STDC__
24			#include <memory.h>
25			#endif
26
27			#include "ukcprog.h"
28
29			#ifndef MSDOS
30			#ifndef __FreeBSD__
31			#ifndef linux
32			extern int sys_nerr, errno;
33			extern char *sys_errlist[];
34			#endif /* !linux */
35			#endif /* !__FreeBSD__ */
36			#endif /* !MSDOS */
37
38
39			/* forward declarations */
40			static void new_buffer PROTO((char ** p_buf, int p_lim, bool p_from_malloc));
41			static void concat PROTO((char *p_buf, int p_pos, int* p_lim,
42			bool p_from_malloc, const char str, int len));
43			static char *long_to_ascii PROTO((unsigned long unum, int base,
44			bool want_uppercase));
45			static char *float_to_ascii PROTO((double d, int precision));
46			static char *efloat_to_ascii PROTO((double d, int precision,
47			bool want_uppercase));
48			static char *gfloat_to_ascii PROTO((double d, int precision,
49			bool want_uppercase));
50
51			#define MAX_NUM_LEN 40 /* buffer sizes used in numeric conversions */
52			#define MAX_FLOAT_LEN 128
53
54
55			/*
56			* new_buffer()
57			* Reallocate the given buffer to twice its current size. *p_lim is the
58			* last usable character in the buffer. The buffer passed in might
59			* not have been allocated by malloc(); this is indicated by *p_from_malloc.
60			*/
61			static void
62			new_buffer(p_buf, p_lim, p_from_malloc)
63			char **p_buf;
64			int *p_lim;
65			bool *p_from_malloc;
66			{
67			char *new;
68			size_t size;
69
70			size = *p_lim + 1;
71
72			if (*p_from_malloc)
73			new = realloc(p_buf, size 2);
74
75			else {
76			if ((new = malloc(size * 2)) != NULL)
77			memcpy(new, *p_buf, size);
78			*p_from_malloc = TRUE;
79			}
80
81			if (new == NULL)
82			panic("malloc returned NULL in new_buffer");
83
84			*p_buf = new;
85			p_lim = (size 2) - 1;
86			}
87
88
89			/*
90			* concat()
91			* Add exactly len bytes of str to the buffer, expanding it with
92			* new_buffer() if we need extra space. Str must be at least len
93			* bytes long.
94			*/
95			static void
96			concat(p_buf, p_pos, p_lim, p_from_malloc, str, len)
97			char **p_buf;
98			int p_pos, p_lim;
99			bool *p_from_malloc;
100			const char *str;
101			int len;
102			{
103			while (p_lim - p_pos < len)
104			new_buffer(p_buf, p_lim, p_from_malloc);
105
106			memcpy(&(p_buf)[p_pos], str, (size_t)len);
107			*p_pos += len;
108			}
109
110
111			static char *
112			long_to_ascii(unum, base, want_uppercase)
113			unsigned long unum;
114			int base;
115			bool want_uppercase;
116			{
117			static char nbuf[MAX_NUM_LEN + 1];
118			char *s;
119			const char *digs;
120
121			s = nbuf + MAX_NUM_LEN;
122
123			digs = want_uppercase ? "0123456789ABCDEF" : "0123456789abcdef";
124			do {
125			*--s = digs[unum % base];
126			unum /= base;
127			} while (unum != 0);
128
129
130			return s;
131			}
132
133
134			static char *
135			float_to_ascii(d, precision)
136			double d;
137			int precision;
138			{
139			static char buf[MAX_FLOAT_LEN];
140
141			sprintf(buf, "%.*f", precision, d);
142			return buf;
143			}
144
145
146			static char *
147			efloat_to_ascii(d, precision, want_uppercase)
148			double d;
149			int precision;
150			bool want_uppercase;
151			{
152			static char buf[MAX_FLOAT_LEN];
153			const char *format;
154
155			if (want_uppercase)
156			format = "%.*E";
157			else
158			format = "%.*e";
159
160			sprintf(buf, format, precision, d);
161			return buf;
162			}
163
164
165
166			static char *
167			gfloat_to_ascii(d, precision, want_uppercase)
168			double d;
169			int precision;
170			bool want_uppercase;
171			{
172			static char buf[MAX_FLOAT_LEN];
173			const char *format;
174
175			if (want_uppercase)
176			format = "%.*G";
177			else
178			format = "%.*g";
179
180			sprintf(buf, format, precision, d);
181			return buf;
182			}
183
184			#ifdef VMS
185			static const char *
186			vms_error_text(unsigned long msgid)
187			{
188			unsigned long status;
189			unsigned short msglen;
190			static char buf[256 + 1];
191			static struct dsc$descriptor_s msg = {
192			sizeof buf - 1, /* length */
193			DSC$K_DTYPE_T, /* data type (8 bit chars) */
194			DSC$K_CLASS_S, /* class (fixed length) */
195			buf
196			};
197
198			status = SYS$GETMSG(msgid, &msglen, &msg, 0, 0);
199			if (status != SS$_NORMAL && status != SS$_MSGNOTFND)
200			sprintf(buf, "Unknown VMS message ID 0x%x", msgid);
201			else
202			buf[msglen] = '\0';
203
204			return buf;
205			}
206			#endif /* VMS */
207
208			/*
209			* formf()
210			* Returns a pointer to a string formatted from the arguments given.
211			* If the string has been obtained from malloc(), the return value will
212			* be different to the buffer pased in; it is the caller's responsibility
213			* to free() this when no longer required.
214			*/
215			char *
216			formf(buffer_space, buffer_size, format, args)
217			char *buffer_space;
218			int buffer_size;
219			const char *format;
220			va_list args;
221			{
222			bool left_justify, print_sign, zero_pad, alternate_form;
223			bool is_negative, precision_given, want_uppercase, from_malloc;
224			int min_field_width, precision, modifier, base, pos, lim, len;
225			const char fmt, alternate_prefix, *s;
226			char *buf, str[2], errno_buffer[42];
227			int alternate_size, saved_errno;
228			unsigned long u;
229			long i;
230			int *ip;
231			double d;
232
233			saved_errno = errno; /* for use later in %m format */
234
235			/*
236			* The formatted string is prepared in a buffer pointed to by buf.
237			* This starts out pointing to a buffer passed in as an argument,
238			* but if this fills, a new one is obtained from malloc().
239			* Pos is the index of the position for the next character
240			* in the output string, and lim is the index of the last
241			* usable character.
242			*/
243			from_malloc = FALSE;
244			buf = buffer_space;
245			lim = buffer_size - 1;
246			pos = 0;
247			fmt = format;
248
249			for (;;) {
250			min_field_width = 0;
251			precision_given = FALSE;
252			precision = 0;
253			modifier = 0;
254			left_justify = FALSE;
255			print_sign = FALSE;
256			zero_pad = FALSE;
257			alternate_form = FALSE;
258
259			/* Find next argument for conversion */
260			while (fmt != '\0' && fmt != '%') {
261			if (pos == lim)
262			new_buffer(&buf, &lim, &from_malloc);
263
264			buf[pos++] = *fmt++;
265			}
266
267			if (*fmt == '\0') {
268			buf[pos] = '\0';
269			return buf; /* end of format string */
270			}
271
272			/* flags, in any order */
273			for (;;) {
274			if (*++fmt == '\0')
275			panic("confused format flags in formf");
276
277			if (*fmt == '-')
278			left_justify = TRUE;
279
280			else if (*fmt == '+')
281			print_sign = TRUE;
282
283			else if (*fmt == '0')
284			zero_pad = TRUE;
285
286			else if (*fmt == '#')
287			alternate_form = TRUE;
288
289			else
290			break; /* end of flags */
291
292			}
293
294			/* minimum field width */
295			if (fmt == '') {
296			min_field_width = va_arg(args, int);
297			++fmt;
298			} else
299			while (isdigit(*fmt)) {
300			min_field_width *= 10;
301			min_field_width += *fmt - '0';
302			++fmt;
303			}
304
305			if (*fmt == '.') {
306
307			/* precision */
308			if (++fmt == '') {
309			precision_given = TRUE;
310			precision = va_arg(args, int);
311			++fmt;
312			} else if (isdigit(*fmt)) {
313			precision_given = TRUE;
314			precision = 0;
315			do {
316			precision *= 10;
317			precision += *fmt - '0';
318			++fmt;
319			} while (isdigit(*fmt));
320			}
321			}
322
323			if (strchr("hlL", *fmt) != NULL)
324			modifier = *fmt++;
325
326			want_uppercase = TRUE;
327			alternate_prefix = "0X";
328			alternate_size = 2;
329			is_negative = FALSE;
330
331			switch (*fmt) {
332			case 'd':
333			case 'i':
334			if (modifier == 'h')
335			i = va_arg(args, short);
336			else if (modifier == 'l')
337			i = va_arg(args, long);
338			else
339			i = va_arg(args, int);
340			is_negative = i < 0;
341			u = is_negative ? -i : i;
342			s = long_to_ascii(u, 10, want_uppercase);
343			break;
344
345			case 'o':
346			base = 8;
347			alternate_prefix = "0";
348			alternate_size = 1;
349			goto gencase;
350			case 'p':
351			alternate_prefix = "0x";
352			alternate_size = 2;
353			want_uppercase = FALSE;
354			base = 16;
355			print_sign = FALSE;
356			u = (unsigned long)va_arg(args, char *);
357			s = long_to_ascii(u, base, want_uppercase);
358			#ifdef MSDOS
359			/* The traditional format for pointers on
360			* MSDOS is segment:offset. NOTE: we depend
361			* on long_to_ascii() returning a buffer with
362			* space before the beginning.
363			*/
364			if ((len = strlen(s)) <= 8) {
365			s -= 8 - len;
366			memset(s, '0', 8 - len);
367
368			--s;
369			memmove(s, s + 1, 4);
370			s[4] = ':';
371			}
372			#endif
373			break;
374			case 'x':
375			alternate_prefix = "0x";
376			alternate_size = 2;
377			want_uppercase = FALSE;
378			/* fall through */;
379			case 'X':
380			base = 16;
381			goto gencase;
382			case 'u':
383			base = 10;
384			gencase: if (modifier == 'h')
385			u = va_arg(args, short);
386			else if (modifier == 'l')
387			u = va_arg(args, long);
388			else
389			u = va_arg(args, int);
390			s = long_to_ascii(u, base, want_uppercase);
391			break;
392
393			case 'c':
394			str[0] = (char)va_arg(args, int); /* promoted char */
395			str[1] = '\0';
396			s = str;
397			print_sign = FALSE;
398			break;
399
400			case '%':
401			str[0] = '%';
402			str[1] = '\0';
403			s = str;
404			print_sign = FALSE;
405			break;
406
407			case 's':
408			s = va_arg(args, char *);
409			if (s == NULL)
410			panic("null pointer for %s in formf");
411			print_sign = FALSE;
412			break;
413			case 'm':
414			if (saved_errno < 0 \|\| saved_errno > sys_nerr \|\|
415			*sys_errlist[saved_errno] == '\0') {
416			sprintf(errno_buffer,
417			"errno %d out of range",
418			saved_errno);
419			s = errno_buffer;
420			} else
421			s = sys_errlist[saved_errno];
422			print_sign = FALSE;
423			break;
424			#ifdef VMS
425			case 'M':
426			s = vms_error_text(va_arg(args, unsigned));
427			print_sign = FALSE;
428			break;
429			#endif /* VMS */
430			case 'f':
431			d = va_arg(args, double);
432			is_negative = d < 0.0;
433			if (is_negative)
434			d = -d;
435			if (!precision_given)
436			precision = 6; /* from K&R */
437			s = float_to_ascii(d, precision);
438			break;
439			case 'e':
440			want_uppercase = FALSE; /* fall through */
441			case 'E':
442			d = va_arg(args, double);
443			is_negative = d < 0.0;
444			if (is_negative)
445			d = -d;
446			if (!precision_given)
447			precision = 6; /* from K&R */
448			s = efloat_to_ascii(d, precision,
449			want_uppercase);
450			break;
451			case 'g':
452			want_uppercase = FALSE; /* fall through */
453			case 'G':
454			d = va_arg(args, double);
455			is_negative = d < 0.0;
456			if (is_negative)
457			d = -d;
458			if (!precision_given)
459			precision = 6; /* from K&R */
460			s = gfloat_to_ascii(d, precision,
461			want_uppercase);
462			break;
463			case 'n':
464			ip = va_arg(args, int *);
465			*ip = pos;
466
467			++fmt; /* step over format character */
468			continue;
469
470			default:
471			panic("illegal format in formf");
472			s = NULL; /* to satisfy gcc */
473			break;
474			}
475
476			len = strlen(s);
477
478			/* truncate strings if requested */
479			if ((fmt == 's' \|\| fmt == 'm')
480			&& precision_given && precision < len)
481			len = precision;
482
483			if (!left_justify) {
484			const char *fillch_str = zero_pad ? "0" : " ";
485
486			if ((is_negative \|\| print_sign) && zero_pad) {
487			concat(&buf, &pos, &lim, &from_malloc,
488			is_negative ? "-" : "+", 1);
489			is_negative = print_sign = FALSE;
490			--min_field_width;
491			}
492
493			if (alternate_form && alternate_prefix != NULL) {
494			concat(&buf, &pos, &lim, &from_malloc,
495			alternate_prefix, alternate_size);
496			min_field_width -= alternate_size;
497			alternate_form = FALSE;
498			}
499
500			while (len < min_field_width) {
501			concat(&buf, &pos, &lim, &from_malloc,
502			fillch_str, 1);
503			--min_field_width;
504			}
505			}
506
507			if (is_negative \|\| print_sign) {
508			concat(&buf, &pos, &lim, &from_malloc,
509			is_negative ? "-" : "+", 1);
510			--min_field_width;
511			}
512
513			if (alternate_form && alternate_prefix != NULL) {
514			concat(&buf, &pos, &lim, &from_malloc,
515			alternate_prefix, alternate_size);
516			min_field_width -= alternate_size;
517			}
518
519
520			concat(&buf, &pos, &lim, &from_malloc, s, len);
521			min_field_width -= len;
522
523			if (left_justify) {
524			while (min_field_width > 0) {
525			concat(&buf, &pos, &lim, &from_malloc, " ", 1);
526			--min_field_width;
527			}
528			}
529
530			++fmt; /* step over format character */
531			}
532			}