src/common/portio.c

#ifndef lint
static const char       RCSid[] = "$Id: portio.c,v 2.12 2005/02/18 16:34:27 greg Exp $";
#endif
/*
 * Portable i/o for binary files
 *
 * External symbols declared in standard.h
 */

#include "copyright.h"

#include <stdio.h>

#include "rtio.h"

#include <math.h>

#ifdef getc_unlocked            /* avoid horrendous overhead of flockfile */
#undef getc
#undef putc
#define getc    getc_unlocked
#define putc    putc_unlocked
#endif


void
putstr(s, fp)                   /* write null-terminated string to fp */
register char  *s;
register FILE  *fp;
{
        do
                putc(*s, fp);
        while (*s++);
}


void
putint(i, siz, fp)              /* write a siz-byte integer to fp */
long  i;
register int  siz;
register FILE  *fp;
{
        while (siz--)
                putc((int)(i>>(siz<<3) & 0xff), fp);
}


void
putflt(f, fp)                   /* put out floating point number */
double  f;
FILE  *fp;
{
        long  m;
        int  e;

        m = frexp(f, &e) * 0x7fffffff;
        if (e > 127) {                  /* overflow */
                m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff;
                e = 127;
        } else if (e < -128) {          /* underflow */
                m = 0;
                e = 0;
        }
        putint(m, 4, fp);
        putint((long)e, 1, fp);
}


char *
getstr(s, fp)                   /* get null-terminated string */
char  *s;
register FILE  *fp;
{
        register char  *cp;
        register int  c;

        cp = s;
        while ((c = getc(fp)) != EOF)
                if ((*cp++ = c) == '\0')
                        return(s);
                
        return(NULL);
}


long
getint(siz, fp)                 /* get a siz-byte integer */
int  siz;
register FILE  *fp;
{
        register int  c;
        register long  r;

        if ((c = getc(fp)) == EOF)
                return(EOF);
        r = 0x80&c ? -1<<8|c : c;               /* sign extend */
        while (--siz > 0) {
                if ((c = getc(fp)) == EOF)
                        return(EOF);
                r <<= 8;
                r |= c;
        }
        return(r);
}


double
getflt(fp)                      /* get a floating point number */
FILE  *fp;
{
        long    l;
        double  d;

        l = getint(4, fp);
        if (l == 0) {
                getc(fp);               /* exactly zero -- ignore exponent */
                return(0.0);
        }
        d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff);
        return(ldexp(d, (int)getint(1, fp)));
}
Revision:	2.13
Committed:	Tue May 3 05:10:13 2005 UTC (20 years, 6 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R7P2, rad3R7P1, rad3R8
Changes since 2.12:	+11 -2 lines
Log Message:	Added handling of overflow and underflow conditions in putflt()
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	greg	2.13	static const char RCSid[] = "$Id: portio.c,v 2.12 2005/02/18 16:34:27 greg Exp $";
3	greg	2.1	#endif
4			/*
5			* Portable i/o for binary files
6	greg	2.6	*
7			* External symbols declared in standard.h
8			*/
9
10	greg	2.7	#include "copyright.h"
11	greg	2.1
12			#include <stdio.h>
13	schorsch	2.8
14			#include "rtio.h"
15	greg	2.1
16	greg	2.9	#include <math.h>
17	greg	2.10
18			#ifdef getc_unlocked /* avoid horrendous overhead of flockfile */
19	greg	2.11	#undef getc
20			#undef putc
21	greg	2.10	#define getc getc_unlocked
22			#define putc putc_unlocked
23			#endif
24	greg	2.1
25	greg	2.3
26	greg	2.6	void
27	greg	2.1	putstr(s, fp) /* write null-terminated string to fp */
28			register char *s;
29			register FILE *fp;
30			{
31			do
32			putc(*s, fp);
33			while (*s++);
34			}
35
36
37	greg	2.6	void
38	greg	2.1	putint(i, siz, fp) /* write a siz-byte integer to fp */
39			long i;
40			register int siz;
41			register FILE *fp;
42			{
43			while (siz--)
44	greg	2.2	putc((int)(i>>(siz<<3) & 0xff), fp);
45	greg	2.1	}
46
47
48	greg	2.6	void
49	greg	2.1	putflt(f, fp) /* put out floating point number */
50	greg	2.2	double f;
51			FILE *fp;
52	greg	2.1	{
53	greg	2.13	long m;
54	greg	2.1	int e;
55
56	greg	2.13	m = frexp(f, &e) * 0x7fffffff;
57			if (e > 127) { /* overflow */
58			m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff;
59			e = 127;
60			} else if (e < -128) { /* underflow */
61			m = 0;
62			e = 0;
63			}
64			putint(m, 4, fp);
65	greg	2.1	putint((long)e, 1, fp);
66			}
67
68
69			char *
70			getstr(s, fp) /* get null-terminated string */
71			char *s;
72			register FILE *fp;
73			{
74			register char *cp;
75			register int c;
76
77			cp = s;
78			while ((c = getc(fp)) != EOF)
79			if ((*cp++ = c) == '\0')
80			return(s);
81
82			return(NULL);
83			}
84
85
86			long
87			getint(siz, fp) /* get a siz-byte integer */
88			int siz;
89			register FILE *fp;
90			{
91			register int c;
92			register long r;
93
94			if ((c = getc(fp)) == EOF)
95			return(EOF);
96			r = 0x80&c ? -1<<8\|c : c; /* sign extend */
97			while (--siz > 0) {
98			if ((c = getc(fp)) == EOF)
99			return(EOF);
100			r <<= 8;
101			r \|= c;
102			}
103			return(r);
104			}
105
106
107			double
108			getflt(fp) /* get a floating point number */
109			FILE *fp;
110			{
111	greg	2.5	long l;
112	greg	2.2	double d;
113	greg	2.1
114	greg	2.5	l = getint(4, fp);
115	greg	2.12	if (l == 0) {
116			getc(fp); /* exactly zero -- ignore exponent */
117			return(0.0);
118			}
119	greg	2.5	d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff);
120	greg	2.1	return(ldexp(d, (int)getint(1, fp)));
121			}