x_create.c

来自「TCP-IP红宝书源代码」· C语言 代码 · 共 84 行

/* x_create.c - x_creat */

#include <conf.h>
#include <kernel.h>
#include <a.out.h>

LOCAL	char	symfile[] = "pm.out";	/* name of object file to search*/

/*------------------------------------------------------------------------
 *  x_creat  -  (command create) create a process given a starting address
 *------------------------------------------------------------------------
 */
COMMAND	x_creat(stdin, stdout, stderr, nargs, args)
int	stdin, stdout, stderr, nargs;
char	*args[];
{
#ifndef FIXME
    fprintf(stderr,"create: create will be rewritten when a future release\n");
    fprintf(stderr,"        determines the format of the core file\n");
#else    
	int	ssize, prio;
	struct	exec	*aoutptr;
	int	dev, len;
	int	pid;
	char	*loc;
	char	*buf;
	Bool	found;
	long	offset;
	struct	nlist	*symptr;
	struct	nlist	*last;
	char	tmp[30];


	if (nargs <4 || nargs > 5) {
	    fprintf(stderr,
		"usage: create procedure stack-size prio [name]\n");
	    return(SYSERR);
	}
	ssize = atoi(args[2]);
	prio  = atoi(args[3]);
	if ( (dev=open(NAMESPACE, symfile, "ro")) == SYSERR) {
		fprintf(stderr, "Cannot open %s\n", symfile);
		return(SYSERR);
	}
	if ( ((int) (buf=(char *)getmem(512)) ) == SYSERR) {
		fprintf(stderr, "no memory\n");
		return(SYSERR);
	}
	strcpy(tmp, "_");
	strcat(tmp, args[1]);
	printf("Looking up %s\n", tmp);
	read(dev, buf, 16);
	aoutptr = (struct exec *)buf;
	offset = (long)  (aoutptr->a_text +  aoutptr->a_data
				 + (unsigned) sizeof(struct exec));
	seek(dev, offset);
	for (found=FALSE ; !found ;) {
		len = read(dev, buf, 42*sizeof(struct nlist));
		if (len <= 0 ) {
			fprintf(stderr, "not found\n");
			close(dev);
			freemem(buf, 512);
			return(SYSERR);
		}
		last = (struct nlist *)&buf[len]; 
		for (symptr=(struct nlist *)buf ; symptr<last ;symptr++) {
		  printf("name: %s, loc: 0x%x\n",
			 symptr->n_un.n_name, symptr->n_value);
			if (symptr->n_type == (N_TEXT|N_EXT) &&
				strncmp(symptr->n_un.n_name,tmp,8)==0) {
				loc = (char *)symptr->n_value;
				found = TRUE;
				break;
			}
		}
	}
	close(dev);
	freemem(buf, 512);
	pid = create(loc, ssize, prio, nargs==5?args[4]:tmp, 0);
	fprintf(stderr, "[%d]\n", pid );
	return(resume(pid));
#endif    
}