tracker/readraw/getbytes.c

/*
 * include needed system headers
 */
#include <stdio.h>       /* include standard i/o library */
#include <stdlib.h>      /* include standard library */
#include <string.h>      /* include string library */
#include <unistd.h>      /* include unix standard library */
#include <sys/types.h>   /* */
#include <sys/stat.h>    /* */
#include <fcntl.h>       /* */
#include <errno.h>       /* error simbol definitions */
#include <time.h>        /* system time definitions */
#include <math.h>        /* math library */


/**
 * Read nbytes at position p of buffer, and fill value
 */

void getbytes_(int *nbytes, char *buffer, int *p, unsigned int *value)

{
    char bytes[4];
    int i;

    for(i=0; i<*nbytes; i++) {
        bytes[i] = *(buffer+(*p)-1+i);
    }
    if(*nbytes == 1)
        *value = 0x000000ff & bytes[0];
    if(*nbytes == 2)
        *value = ((bytes[0]<<8)&0x0000ff00) |
            (bytes[1]&0x000000ff);
    if(*nbytes == 4)
        *value = ((bytes[0]<<24)&0xff000000) |
            ((bytes[1]<<16)&0x00ff0000) |
            ((bytes[2]<<8)&0x0000ff00) |
            (bytes[3]&0x000000ff);

    *p += *nbytes;

    return;
}
1	/*
2	* include needed system headers
3	*/
4	#include <stdio.h> /* include standard i/o library */
5	#include <stdlib.h> /* include standard library */
6	#include <string.h> /* include string library */
7	#include <unistd.h> /* include unix standard library */
8	#include <sys/types.h> /* */
9	#include <sys/stat.h> /* */
10	#include <fcntl.h> /* */
11	#include <errno.h> /* error simbol definitions */
12	#include <time.h> /* system time definitions */
13	#include <math.h> /* math library */
14
15
16	/**
17	* Read nbytes at position p of buffer, and fill value
18	*/
19
20	void getbytes_(int nbytes, char buffer, int p, unsigned int value)
21
22	{
23	char bytes[4];
24	int i;
25
26	for(i=0; i<*nbytes; i++) {
27	bytes[i] = (buffer+(p)-1+i);
28	}
29	if(*nbytes == 1)
30	*value = 0x000000ff & bytes[0];
31	if(*nbytes == 2)
32	*value = ((bytes[0]<<8)&0x0000ff00) \|
33	(bytes[1]&0x000000ff);
34	if(*nbytes == 4)
35	*value = ((bytes[0]<<24)&0xff000000) \|
36	((bytes[1]<<16)&0x00ff0000) \|
37	((bytes[2]<<8)&0x0000ff00) \|
38	(bytes[3]&0x000000ff);
39
40	p += nbytes;
41
42	return;
43	}