ikarus/src/ikarus-process.c

81 lines
1.9 KiB
C

#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "ikarus-data.h"
#include <errno.h>
extern ikptr ikrt_io_error();
static int
list_length(ikptr x){
int n = 0;
while(tagof(x) == pair_tag){
n++;
x = ref(x, off_cdr);
}
return n;
}
static char**
list_to_vec(ikptr x){
int n = list_length(x);
char** vec = malloc((n+1) * sizeof(char*));
if (vec == NULL) exit(-1);
int i;
for(i=0; i<n; i++){
vec[i] = (char*)ref(x, off_car) + off_bytevector_data;
x = ref(x, off_cdr);
}
vec[n] = 0;
return vec;
}
ikptr
ikrt_process(ikptr rvec, ikptr cmd, ikptr argv, ikpcb* pcb){
int infds[2];
int outfds[2];
int errfds[2];
if(pipe(infds)) return ikrt_io_error();
if(pipe(outfds)) return ikrt_io_error();
if(pipe(errfds)) return ikrt_io_error();
pid_t pid = fork();
if(pid == 0){
/* child */
if(close(infds[1])) exit(1);
if(close(outfds[0])) exit(1);
if(close(errfds[0])) exit(1);
if(close(0)) exit(1);
if(dup(infds[0]) == -1) exit(1);
if(close(1)) exit(1);
if(dup(outfds[1]) == -1) exit(1);
if(close(2)) exit(2);
if(dup(errfds[1]) == -1) exit(1);
execvp((char*)cmd+off_bytevector_data, list_to_vec(argv));
fprintf(stderr, "failed to exec %s: %s\n",
(char*)cmd+off_bytevector_data,
strerror(errno));
exit(-1);
} else if(pid > 0){
/* parent */
close(infds[0]); /* ignore errors */
close(outfds[1]);
close(errfds[1]);
ref(rvec,off_vector_data+0*wordsize) = fix(pid);
ref(rvec,off_vector_data+1*wordsize) = fix(infds[1]);
ref(rvec,off_vector_data+2*wordsize) = fix(outfds[0]);
ref(rvec,off_vector_data+3*wordsize) = fix(errfds[0]);
return rvec;
} else {
return ikrt_io_error();
}
}
ikptr
ikrt_waitpid(ikptr pid, ikpcb* pcb){
int status;
waitpid(unfix(pid), &status, 0);
return fix(status);
}