ref: c1d40df49550393f3afe53fb6e6d500dfa8eb7a8
dir: /sys/src/ape/lib/ap/plan9/execve.c/
#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 buf[1024]; _RFORK(RFCENVG); /* * To pass _fdinfo[] across exec, put lines like * fd flags oflags * in $_fdinfo (for open fd's) */ f = _CREATE("/env/_fdinfo", OWRITE|OCEXEC, 0666); ss = buf; for(i = 0; i<OPEN_MAX; i++){ if(i == f) continue; fi = &_fdinfo[i]; flags = fi->flags; if(flags&FD_CLOEXEC){ _CLOSE(i); fi->flags = 0; fi->oflags = 0; }else if(flags&FD_ISOPEN){ if(f < 0) continue; ss = _ultoa(ss, i); *ss++ = ' '; ss = _ultoa(ss, flags); *ss++ = ' '; ss = _ultoa(ss, fi->oflags); *ss++ = '\n'; n = ss-buf; if(n > sizeof(buf)-50){ if(_WRITE(f, buf, n) != n) break; ss = buf; } } } if(f >= 0){ 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("/env/_sighdlr", OWRITE|OCEXEC, 0666); if(f >= 0){ ss = buf; for(i = 0; i <=MAXSIG; i++) { if(_sighdlr[i] == SIG_IGN) { ss = _ultoa(ss, i); *ss++ = ' '; n = ss-buf; if(n > sizeof(buf)-20){ if(_WRITE(f, buf, n) != n) break; ss = buf; } } } if(ss > buf) _WRITE(f, buf, ss-buf); _CLOSE(f); } if(envp){ for(e = (char**)envp; (ss = *e); e++) { if(strncmp(ss, "#()fn ", 6)==0){ if((se = strchr(ss+6, '{'))==0) continue; while(se[-1]==' ') se--; n = se-(ss+6); if(n <= 0 || n >= sizeof(buf)-8) continue; /* name too long */ memcpy(buf, "/env/fn#", 8); memcpy(buf+8, ss+6, n); buf[8+n] = '\0'; f = _CREATE(buf, OWRITE|OCEXEC, 0666); if(f < 0) continue; ss += 3; /* past #() */ _WRITE(f, ss, strlen(ss)); _CLOSE(f); } else { if((se = strchr(ss, '='))==0) continue; n = se-ss; if(n <= 0 || n >= sizeof(buf)-5) continue; /* name too long */ memcpy(buf, "/env/", 5); memcpy(buf+5, ss, n); buf[5+n] = '\0'; f = _CREATE(buf, OWRITE|OCEXEC, 0666); if(f < 0) continue; ss = ++se; /* past = */ se += strlen(se); while((n = (se - ss)) > 0){ if(n > sizeof(buf)) n = sizeof(buf); /* decode nulls (see _envsetup()) */ for(i=0; i<n; i++) if((buf[i] = ss[i]) == 1) buf[i] = 0; if(_WRITE(f, buf, n) != n) break; ss += n; } _CLOSE(f); } } } n = _EXEC(name, argv); _syserrno(); return n; }