Subversion Repositories planix.SVN

#include "lib.h"
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include "sys9.h"

extern char **environ;

int
execve(const char *name, const char *argv[], const char *envp[])
{
        int n, f, i;
        char **e, *ss, *se;
        Fdinfo *fi;
        unsigned long flags;
        char nam[256+5];
        char buf[1000];

        _RFORK(RFCENVG);
        /*
         * To pass _fdinfo[] across exec, put lines like
         *   fd flags oflags
         * in $_fdinfo (for open fd's)
         */

        f = _CREATE("#e/_fdinfo", OWRITE, 0666);
        ss = buf;
        for(n = 0; n<OPEN_MAX; n++){
                fi = &_fdinfo[n];
                flags = fi->flags;
                if(flags&FD_CLOEXEC){
                        _CLOSE(n);
                        fi->flags = 0;
                        fi->oflags = 0;
                }else if(flags&FD_ISOPEN){
                        ss = _ultoa(ss, n);
                        *ss++ = ' ';
                        ss = _ultoa(ss, flags);
                        *ss++ = ' ';
                        ss = _ultoa(ss, fi->oflags);
                        *ss++ = '\n';
                        if(ss-buf < sizeof(buf)-50){
                                _WRITE(f, buf, ss-buf);
                                ss = buf;
                        }
                }
        }
        if(ss > buf)
                _WRITE(f, buf, ss-buf);
        _CLOSE(f);
        /*
         * To pass _sighdlr[] across exec, set $_sighdlr
         * to list of blank separated fd's that have
         * SIG_IGN (the rest will be SIG_DFL).
         * We write the variable, even if no signals
         * are ignored, in case the current value of the
         * variable ignored some.
         */
        f = _CREATE("#e/_sighdlr", OWRITE, 0666);
        if(f >= 0){
                ss = buf;
                for(i = 0; i <=MAXSIG && ss < &buf[sizeof(buf)]-5; i++) {
                        if(_sighdlr[i] == SIG_IGN) {
                                ss = _ultoa(ss, i);
                                *ss++ = ' ';
                        }
                }
                _WRITE(f, buf, ss-buf);
                _CLOSE(f);
        }
        if(envp){
                strcpy(nam, "#e/");
                for(e = (char **)envp; (ss = *e); e++) {
                        se = strchr(ss, '=');
                        if(!se || ss==se)
                                continue;       /* what is name? value? */
                        n = se-ss;
                        if(n >= sizeof(nam)-3)
                                n = sizeof(nam)-3-1;
                        memcpy(nam+3, ss, n);
                        nam[3+n] = 0;
                        f = _CREATE(nam, OWRITE, 0666);
                        if(f < 0)
                                continue;
                        se++; /* past = */
                        n = strlen(se);
                        /* temporarily decode nulls (see _envsetup()) */
                        for(i=0; i < n; i++)
                                if(se[i] == 1)
                                        se[i] = 0;
                        _WRITE(f, se, n);
                        /* put nulls back */
                        for(i=0; i < n; i++)
                                if(se[i] == 0)
                                        se[i] = 1;
                        _CLOSE(f);
                }
        }
        n = _EXEC(name, argv);
        _syserrno();
        return n;
}