src/common/portio.c

#ifndef lint
static const char       RCSid[] = "$Id: portio.c,v 2.20 2019/07/04 02:06:32 greg Exp $";
#endif
/*
 * Portable i/o for binary files
 *
 * External symbols declared in rtio.h
 */

#include "copyright.h"

#include "rtio.h"

#include <math.h>


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


void
putint(                         /* write a siz-byte integer to fp */
        long  i,
        int  siz,
        FILE  *fp
)
{
        siz <<= 3;
        while ((siz -= 8) >= 0)
                putc((int)(i>>siz & 0xff), fp);
}


void
putflt(                         /* 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);
}


int
putbinary(                      /* fwrite() replacement for small objects */
        const void *p,
        int elsiz,
        int nel,
        FILE *fp)
{
        const char      *s = (const char *)p;
        int             nbytes = elsiz*nel;

        if (nbytes > 256)
                return(fwrite(p, elsiz, nel, fp));
        
        while (nbytes-- > 0)
                if (putc(*s++, fp) == EOF)
                        return((elsiz*nel - nbytes)/elsiz);

        return(nel);
}


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

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


long
getint(                         /* get a siz-byte integer */
        int  siz,
        FILE  *fp
)
{
        int  c;
        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(                         /* get a floating point number */
        FILE  *fp
)
{
        long    l;
        double  d;

        l = getint(4, fp);
        if (l == EOF && feof(fp))       /* EOF? */
                return((double)EOF);
        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)));
}


int
getbinary(                      /* fread() replacement for small objects */
        void *p,
        int elsiz,
        int nel,
        FILE *fp)
{
        char    *s = (char *)p;
        int     nbytes = elsiz*nel;
        int     c;

        if (nbytes > 256)
                return(fread(p, elsiz, nel, fp));
        
        while (nbytes-- > 0) {
                if ((c = getc(fp)) == EOF)
                        return((elsiz*nel - nbytes)/elsiz);
                *s++ = c;
        }
        return(nel);
}
Revision:	2.21
Committed:	Fri Jul 5 03:04:22 2019 UTC (6 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.20:	+3 -2 lines
Log Message:	Added error checking to putbinary()
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	greg	2.21	static const char RCSid[] = "$Id: portio.c,v 2.20 2019/07/04 02:06:32 greg Exp $";
3	greg	2.1	#endif
4			/*
5			* Portable i/o for binary files
6	greg	2.6	*
7	greg	2.14	* External symbols declared in rtio.h
8	greg	2.6	*/
9
10	greg	2.7	#include "copyright.h"
11	greg	2.1
12	schorsch	2.8	#include "rtio.h"
13	greg	2.1
14	greg	2.9	#include <math.h>
15	greg	2.10
16	greg	2.3
17	greg	2.6	void
18	greg	2.15	putstr( /* write null-terminated string to fp */
19			char *s,
20			FILE *fp
21			)
22	greg	2.1	{
23			do
24			putc(*s, fp);
25			while (*s++);
26			}
27
28
29	greg	2.6	void
30	greg	2.15	putint( /* write a siz-byte integer to fp */
31			long i,
32			int siz,
33			FILE *fp
34			)
35	greg	2.1	{
36	greg	2.18	siz <<= 3;
37			while ((siz -= 8) >= 0)
38			putc((int)(i>>siz & 0xff), fp);
39	greg	2.1	}
40
41
42	greg	2.6	void
43	greg	2.15	putflt( /* put out floating point number */
44			double f,
45			FILE *fp
46			)
47	greg	2.1	{
48	greg	2.13	long m;
49	greg	2.1	int e;
50
51	greg	2.13	m = frexp(f, &e) * 0x7fffffff;
52			if (e > 127) { /* overflow */
53			m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff;
54			e = 127;
55			} else if (e < -128) { /* underflow */
56			m = 0;
57			e = 0;
58			}
59			putint(m, 4, fp);
60	greg	2.1	putint((long)e, 1, fp);
61			}
62
63
64	greg	2.16	int
65			putbinary( /* fwrite() replacement for small objects */
66	greg	2.19	const void *p,
67	greg	2.16	int elsiz,
68			int nel,
69			FILE *fp)
70			{
71	greg	2.19	const char s = (const char )p;
72			int nbytes = elsiz*nel;
73	greg	2.16
74	greg	2.20	if (nbytes > 256)
75	greg	2.19	return(fwrite(p, elsiz, nel, fp));
76	greg	2.16
77			while (nbytes-- > 0)
78	greg	2.21	if (putc(*s++, fp) == EOF)
79			return((elsiz*nel - nbytes)/elsiz);
80	greg	2.16
81			return(nel);
82			}
83
84
85	greg	2.1	char *
86	greg	2.15	getstr( /* get null-terminated string */
87			char *s,
88			FILE *fp
89			)
90	greg	2.1	{
91	greg	2.15	char *cp;
92			int c;
93	greg	2.1
94			cp = s;
95			while ((c = getc(fp)) != EOF)
96			if ((*cp++ = c) == '\0')
97			return(s);
98
99			return(NULL);
100			}
101
102
103			long
104	greg	2.15	getint( /* get a siz-byte integer */
105			int siz,
106			FILE *fp
107			)
108	greg	2.1	{
109	greg	2.15	int c;
110			long r;
111	greg	2.1
112			if ((c = getc(fp)) == EOF)
113			return(EOF);
114			r = 0x80&c ? -1<<8\|c : c; /* sign extend */
115			while (--siz > 0) {
116			if ((c = getc(fp)) == EOF)
117			return(EOF);
118			r <<= 8;
119			r \|= c;
120			}
121			return(r);
122			}
123
124
125			double
126	greg	2.15	getflt( /* get a floating point number */
127			FILE *fp
128			)
129	greg	2.1	{
130	greg	2.5	long l;
131	greg	2.2	double d;
132	greg	2.1
133	greg	2.5	l = getint(4, fp);
134	greg	2.15	if (l == EOF && feof(fp)) /* EOF? */
135			return((double)EOF);
136	greg	2.12	if (l == 0) {
137			getc(fp); /* exactly zero -- ignore exponent */
138			return(0.0);
139			}
140	greg	2.5	d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff);
141	greg	2.1	return(ldexp(d, (int)getint(1, fp)));
142			}
143	greg	2.16
144
145			int
146			getbinary( /* fread() replacement for small objects */
147	greg	2.19	void *p,
148	greg	2.16	int elsiz,
149			int nel,
150			FILE *fp)
151			{
152	greg	2.19	char s = (char )p;
153	greg	2.16	int nbytes = elsiz*nel;
154			int c;
155
156	greg	2.20	if (nbytes > 256)
157	greg	2.19	return(fread(p, elsiz, nel, fp));
158	greg	2.16
159			while (nbytes-- > 0) {
160			if ((c = getc(fp)) == EOF)
161			return((elsiz*nel - nbytes)/elsiz);
162			*s++ = c;
163			}
164			return(nel);
165			}