Try this: the worst limitation is that the fifo number
is hardcoded - to be fixed soon.
--
---------------------------------------------------------
Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com
/* USER SIDE PRINTF
* Copyright Finite State Machine Labs Inc. March 2001.
* by Victor Yodaiken
*
* Released under version 2 of the GPL.
* All rights not specifically granted under GPL
* are reserved.
*
* */
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#define BUFSIZE 500
int buf[BUFSIZE];
int sz, IN;
void format_and_print(int fmtlen, char *fmt, char *data);
int main(){
IN = open("/dev/rtf0",O_RDONLY);
if(IN < 0){
fprintf(stderr,"Can't open the fifo\n");
exit(-1);
}
while( read(IN,&sz,sizeof(sz)) == sizeof(sz)){
/* this is the start */
if(read(IN,buf,sz) != sz){
printf("Format error!\n");
}
else{
int fmtlen = strlen( (char *)buf);
char *fmt = (char *)buf;
char *data = ((char *)buf)+fmtlen+1;
format_and_print(fmtlen,fmt,data);
}
}
return 0;
}
static int find_delim(const char *s,int index){
while( s[index] && (s[index] !='%'))index++;
return index;
}
static void ncpy(char *d, char *s,int n){
while(n--){ *d++ = *s++;}
return;
}
void format_and_print(int fmtlen, char *fmt, char *data)
{
double D;
int I;
char *S;
char delim;
int i,start=0;
while(fmt[start]){
i = find_delim(fmt,start);
delim = fmt[i];
fmt[i] = 0;
fputs(&fmt[start],stdout);
if(delim) // not at the end, must be a %
{
start = i+2; // skip format letter
switch(fmt[i+1]) {
case 's':
S = data;
data += strlen(S)+1;
printf("%s",S);
break;
case 'd':
ncpy((char *)&I,data,sizeof(I));
printf("%d",I);
data += sizeof(I);
break;
case 'c': /* C "promotes" chars*/
ncpy((char *)&I,data,sizeof(I));
printf("%c",I);
data += sizeof(I);
break;
case 'f':
ncpy((char *)&D,data,sizeof(D));
printf("%f",D);
data += sizeof(D);
break;
}
}else start = i; // we're done.
}
fflush(stdout);
}
/* USER SIDE PRINTF
* Copyright Finite State Machine Labs Inc. March 2001.
* by Victor Yodaiken
*
* Released under version 2 of the GPL.
* All rights not specifically granted under GPL
* are reserved.
*/
#include <rtl.h>
#include <rtl_fifo.h>
#include <time.h>
#include <rtl_sched.h>
#include <rtl_sync.h>
#include <pthread.h>
#include <posix/unistd.h>
//#include <stdarg.h>
void user_printf(const char *fmt,...);
int OUT;
#define eprint rtl_printf // so I could debug this code in user space
#define BUFSIZE 500
char buf[BUFSIZE];
int init_module(void){
rtf_destroy(0);
if ( (OUT = open("/dev/rtf0",O_WRONLY | O_NONBLOCK | O_CREAT )) < 0)
{
rtl_printf("Example cannot open fifo\n");
rtl_printf("Error number is %d\n",errno);
return -1;
}
user_printf("Test from init code\n"); //DEBUG
return 0;
}
void cleanup_module(void){
close(OUT);
}
static int fixcopy(int space, char *dest, void *v,int sz){
char *c = (char *)v;
if(sz > space){
eprint("RTL error: user_printf out of space\n");
return -1;
}
else{
while(sz > 0){*dest++ = *c++; sz--;}
}
return 0;
}
static int safecopy(int space, char *dest, const char *src){
int len = strlen(src)+1;
if(len > space){
eprint("RTL error: Can't user_printf very long strings\n");
return -1;
}
strncpy(dest,src,len);
return len;
}
void user_printf(const char *fmt,...){
int len,i,d,l;
char *s;
double f;
va_list ap;
/* dump the character string */
if ( (len = safecopy(BUFSIZE, buf,fmt)) < 0)return;
/* then copy the characters */
va_start(ap, fmt);
for(i=0; i < strlen(fmt); i++){
if(fmt[i] == '%') switch(fmt[i+1]) {
case 's': /* string */
s = va_arg(ap, char *);
l = safecopy(BUFSIZE -len, buf+len,s);
if(l<0)return;
len += l;
break;
case 'd': /* int */
case 'c': /* char is in an int */
d = va_arg(ap, int);
if(fixcopy(BUFSIZE-len, buf+len, &d,sizeof(d)))
return;
len += sizeof(d);
break;
case 'f': /* double */
f = va_arg(ap, double);
if(fixcopy(BUFSIZE-len, buf+len, &f,sizeof(f)))
return;
len += sizeof(f);
break;
}
}
rtl_printf("user printf writes %d bytes\n",len);//DEBUG
write(OUT,&len,sizeof(len));
write(OUT,buf,len);
}
