1 /*- 2 * Copyright (c) 1980, 1991 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char sccsid[] = "@(#)sem.c 5.11 (Berkeley) 04/04/91"; 10 #endif /* not lint */ 11 12 #include "sh.h" 13 #include "sh.proc.h" 14 #include <sys/file.h> 15 #include <sys/ioctl.h> 16 #include "pathnames.h" 17 18 /* 19 * C shell 20 */ 21 22 static int nosigchld = 0, osigmask; 23 static int onosigchld = 0, oosigmask; 24 /*VARARGS 1*/ 25 execute(t, wanttty, pipein, pipeout) 26 register struct command *t; 27 int wanttty, *pipein, *pipeout; 28 { 29 bool forked = 0; 30 struct biltins *bifunc; 31 int pid = 0; 32 int pv[2]; 33 34 if (t == 0) 35 return; 36 if ((t->t_dflg & F_AMPERSAND) && wanttty > 0) 37 wanttty = 0; 38 switch (t->t_dtyp) { 39 40 case NODE_COMMAND: 41 if ((t->t_dcom[0][0] & (QUOTE|TRIM)) == QUOTE) 42 (void) strcpy(t->t_dcom[0], t->t_dcom[0] + 1); 43 if ((t->t_dflg & F_REPEAT) == 0) 44 Dfix(t); /* $ " ' \ */ 45 if (t->t_dcom[0] == 0) 46 return; 47 /* fall into... */ 48 49 case NODE_PAREN: 50 if (t->t_dflg & F_PIPEOUT) 51 mypipe(pipeout); 52 /* 53 * Must do << early so parent will know 54 * where input pointer should be. 55 * If noexec then this is all we do. 56 */ 57 if (t->t_dflg & F_READ) { 58 (void) close(0); 59 heredoc(t->t_dlef); 60 if (noexec) 61 (void) close(0); 62 } 63 if (noexec) 64 break; 65 66 set("status", "0"); 67 68 /* 69 * This mess is the necessary kludge to handle the prefix 70 * builtins: nice, nohup, time. These commands can also 71 * be used by themselves, and this is not handled here. 72 * This will also work when loops are parsed. 73 */ 74 while (t->t_dtyp == NODE_COMMAND) 75 if (eq(t->t_dcom[0], "nice")) 76 if (t->t_dcom[1]) 77 if (index("+-", t->t_dcom[1][0])) 78 if (t->t_dcom[2]) { 79 setname("nice"); 80 t->t_nice = getn(t->t_dcom[1]); 81 lshift(t->t_dcom, 2); 82 t->t_dflg |= F_NICE; 83 } else 84 break; 85 else { 86 t->t_nice = 4; 87 lshift(t->t_dcom, 1); 88 t->t_dflg |= F_NICE; 89 } 90 else 91 break; 92 else if (eq(t->t_dcom[0], "nohup")) 93 if (t->t_dcom[1]) { 94 t->t_dflg |= F_NOHUP; 95 lshift(t->t_dcom, 1); 96 } else 97 break; 98 else if (eq(t->t_dcom[0], "time")) 99 if (t->t_dcom[1]) { 100 t->t_dflg |= F_TIME; 101 lshift(t->t_dcom, 1); 102 } else 103 break; 104 else 105 break; 106 /* 107 * Check if we have a builtin function and remember which one. 108 */ 109 bifunc = t->t_dtyp == 110 NODE_COMMAND ? isbfunc(t) : (struct biltins *) 0; 111 112 /* 113 * We fork only if we are timed, or are not the end of 114 * a parenthesized list and not a simple builtin function. 115 * Simple meaning one that is not pipedout, niced, nohupped, 116 * or &'d. 117 * It would be nice(?) to not fork in some of these cases. 118 */ 119 if (((t->t_dflg & F_TIME) || (t->t_dflg & F_NOFORK) == 0 && 120 (!bifunc || 121 t->t_dflg & (F_PIPEOUT|F_AMPERSAND|F_NICE|F_NOHUP)))) 122 #ifdef VFORK 123 if (t->t_dtyp == NODE_PAREN || 124 t->t_dflg&(F_REPEAT|F_AMPERSAND) || bifunc) 125 #endif 126 { forked++; 127 if (wanttty >= 0 && !nosigchld) { 128 osigmask = sigblock(sigmask(SIGCHLD)); 129 nosigchld = 1; 130 } 131 132 pid = pfork(t, wanttty); 133 if (pid == 0 && nosigchld) { 134 sigsetmask(osigmask); 135 nosigchld = 0; 136 } 137 } 138 #ifdef VFORK 139 else { 140 sig_t vffree; 141 int ochild, osetintr, ohaderr, odidfds; 142 int oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp; 143 long omask; 144 145 /* 146 * Prepare for the vfork by saving everything 147 * that the child corrupts before it exec's. 148 * Note that in some signal implementations 149 * which keep the signal info in user space 150 * (e.g. Sun's) it will also be necessary to 151 * save and restore the current sigvec's for 152 * the signals the child touches before it 153 * exec's. 154 */ 155 if (wanttty >= 0 && !nosigchld && !noexec) { 156 osigmask = sigblock(sigmask(SIGCHLD)); 157 nosigchld = 1; 158 } 159 omask = sigblock(sigmask(SIGCHLD)); 160 ochild = child; osetintr = setintr; 161 ohaderr = haderr; odidfds = didfds; 162 oSHIN = SHIN; oSHOUT = SHOUT; 163 oSHDIAG = SHDIAG; oOLDSTD = OLDSTD; otpgrp = tpgrp; 164 oosigmask = osigmask; onosigchld = nosigchld; 165 Vsav = Vdp = 0; Vav = 0; 166 pid = vfork(); 167 if (pid < 0) { 168 (void) sigsetmask(omask); 169 error("No more processes"); 170 } 171 forked++; 172 if (pid) { /* parent */ 173 child = ochild; setintr = osetintr; 174 haderr = ohaderr; didfds = odidfds; 175 SHIN = oSHIN; 176 SHOUT = oSHOUT; SHDIAG = oSHDIAG; 177 OLDSTD = oOLDSTD; tpgrp = otpgrp; 178 osigmask = oosigmask; nosigchld = onosigchld; 179 xfree(Vsav); Vsav = 0; 180 xfree(Vdp); Vdp = 0; 181 xfree((char *)Vav); Vav = 0; 182 /* this is from pfork() */ 183 palloc(pid, t); 184 (void) sigsetmask(omask); 185 } else { /* child */ 186 /* this is from pfork() */ 187 int pgrp; 188 bool ignint = 0; 189 190 if (nosigchld) { 191 sigsetmask(osigmask); 192 nosigchld = 0; 193 } 194 if (setintr) 195 ignint = (tpgrp == -1 && 196 (t->t_dflg&F_NOINTERRUPT)) || 197 gointr && eq(gointr, "-"); 198 pgrp = pcurrjob ? pcurrjob->p_jobid : getpid(); 199 child++; 200 if (setintr) { 201 setintr = 0; 202 #ifdef notdef 203 (void) signal(SIGCHLD, SIG_DFL); 204 #endif 205 (void) signal(SIGINT, ignint ? 206 SIG_IGN : vffree); 207 (void) signal(SIGQUIT, ignint ? 208 SIG_IGN : SIG_DFL); 209 if (wanttty >= 0) { 210 (void) signal(SIGTSTP, SIG_DFL); 211 (void) signal(SIGTTIN, SIG_DFL); 212 (void) signal(SIGTTOU, SIG_DFL); 213 } 214 (void) signal(SIGTERM, parterm); 215 } else if (tpgrp == -1 && 216 (t->t_dflg&F_NOINTERRUPT)) { 217 (void) signal(SIGINT, SIG_IGN); 218 (void) signal(SIGQUIT, SIG_IGN); 219 } 220 if (wanttty >= 0 && tpgrp >= 0) 221 (void) setpgrp(0, pgrp); 222 if (wanttty > 0) 223 (void) ioctl(FSHTTY, TIOCSPGRP, 224 (char *)&pgrp); 225 if (tpgrp > 0) 226 tpgrp = 0; 227 if (t->t_dflg & F_NOHUP) 228 (void) signal(SIGHUP, SIG_IGN); 229 if (t->t_dflg & F_NICE) 230 (void) setpriority(PRIO_PROCESS, 231 0, t->t_nice); 232 } 233 234 } 235 #endif 236 if (pid != 0) { 237 /* 238 * It would be better if we could wait for the 239 * whole job when we knew the last process 240 * had been started. Pwait, in fact, does 241 * wait for the whole job anyway, but this test 242 * doesn't really express our intentions. 243 */ 244 if (didfds==0 && t->t_dflg&F_PIPEIN) { 245 (void) close(pipein[0]); 246 (void) close(pipein[1]); 247 } 248 if ((t->t_dflg & F_PIPEOUT) == 0) { 249 if (nosigchld) { 250 #ifdef foobarbaz 251 printf("DID\n"); 252 #endif 253 sigsetmask(osigmask); 254 nosigchld = 0; 255 } 256 if ((t->t_dflg & F_AMPERSAND) == 0) 257 pwait(); 258 } 259 break; 260 } 261 doio(t, pipein, pipeout); 262 if (t->t_dflg & F_PIPEOUT) { 263 (void) close(pipeout[0]); 264 (void) close(pipeout[1]); 265 } 266 267 /* 268 * Perform a builtin function. 269 * If we are not forked, arrange for possible stopping 270 */ 271 if (bifunc) { 272 func(t, bifunc); 273 if (forked) 274 exitstat(); 275 break; 276 } 277 if (t->t_dtyp != NODE_PAREN) { 278 doexec(t); 279 /*NOTREACHED*/ 280 } 281 /* 282 * For () commands must put new 0,1,2 in FSH* and recurse 283 */ 284 OLDSTD = dcopy(0, FOLDSTD); 285 SHOUT = dcopy(1, FSHOUT); 286 SHDIAG = dcopy(2, FSHDIAG); 287 (void) close(SHIN); 288 SHIN = -1; 289 didfds = 0; 290 wanttty = -1; 291 t->t_dspr->t_dflg |= t->t_dflg & F_NOINTERRUPT; 292 execute(t->t_dspr, wanttty); 293 exitstat(); 294 295 case NODE_PIPE: 296 t->t_dcar->t_dflg |= F_PIPEOUT | 297 (t->t_dflg & (F_PIPEIN|F_AMPERSAND|F_STDERR|F_NOINTERRUPT)); 298 execute(t->t_dcar, wanttty, pipein, pv); 299 t->t_dcdr->t_dflg |= F_PIPEIN | 300 (t->t_dflg & 301 (F_PIPEOUT|F_AMPERSAND|F_NOFORK|F_NOINTERRUPT)); 302 if (wanttty > 0) 303 wanttty = 0; /* got tty already */ 304 execute(t->t_dcdr, wanttty, pv, pipeout); 305 break; 306 307 case NODE_LIST: 308 if (t->t_dcar) { 309 t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; 310 execute(t->t_dcar, wanttty); 311 /* 312 * In strange case of A&B make a new job after A 313 */ 314 if (t->t_dcar->t_dflg&F_AMPERSAND && t->t_dcdr && 315 (t->t_dcdr->t_dflg&F_AMPERSAND) == 0) 316 pendjob(); 317 } 318 if (t->t_dcdr) { 319 t->t_dcdr->t_dflg |= 320 t->t_dflg & (F_NOFORK|F_NOINTERRUPT); 321 execute(t->t_dcdr, wanttty); 322 } 323 break; 324 325 case NODE_OR: 326 case NODE_AND: 327 if (t->t_dcar) { 328 t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; 329 execute(t->t_dcar, wanttty); 330 if ((getn(value("status")) == 0) != 331 (t->t_dtyp == NODE_AND)) 332 return; 333 } 334 if (t->t_dcdr) { 335 t->t_dcdr->t_dflg |= 336 t->t_dflg & (F_NOFORK|F_NOINTERRUPT); 337 execute(t->t_dcdr, wanttty); 338 } 339 break; 340 } 341 /* 342 * Fall through for all breaks from switch. 343 * 344 * If there will be no more executions of this command, flush all 345 * file descriptors. Places that turn on the F_REPEAT bit are 346 * responsible for doing donefds after the last re-execution 347 */ 348 if (didfds && !(t->t_dflg & F_REPEAT)) 349 donefds(); 350 } 351 352 #ifdef VFORK 353 vffree() 354 { 355 register char **v; 356 357 if (v = gargv) 358 gargv = 0, xfree((char *)v); 359 if (v = pargv) 360 pargv = 0, xfree((char *)v); 361 _exit(1); 362 } 363 #endif 364 365 /* 366 * Perform io redirection. 367 * We may or maynot be forked here. 368 */ 369 doio(t, pipein, pipeout) 370 register struct command *t; 371 int *pipein, *pipeout; 372 { 373 register char *cp; 374 register int flags = t->t_dflg; 375 376 if (didfds || (flags & F_REPEAT)) 377 return; 378 if ((flags & F_READ) == 0) { /* F_READ already done */ 379 (void) close(0); 380 if (cp = t->t_dlef) { 381 cp = globone(Dfix1(cp)); 382 xfree(cp); 383 if (open(cp, 0) < 0) 384 Perror(cp); 385 } else if (flags & F_PIPEIN) { 386 (void) dup(pipein[0]); 387 (void) close(pipein[0]); 388 (void) close(pipein[1]); 389 } else if ((flags & F_NOINTERRUPT) && tpgrp == -1) { 390 (void) close(0); 391 (void) open(_PATH_DEVNULL, 0); 392 } else 393 (void) dup(OLDSTD); 394 } 395 (void) close(1); 396 if (cp = t->t_drit) { 397 cp = globone(Dfix1(cp)); 398 xfree(cp); 399 if (!(flags & F_APPEND) || open(cp, O_WRONLY|O_APPEND, 0) < 0) { 400 if (!(flags & F_OVERWRITE) && adrof("noclobber")) { 401 if (flags & F_APPEND) 402 Perror(cp); 403 chkclob(cp); 404 } 405 if (creat(cp, 0666) < 0) 406 Perror(cp); 407 } 408 } else if (flags & F_PIPEOUT) 409 (void) dup(pipeout[1]); 410 else 411 (void) dup(SHOUT); 412 413 (void) close(2); 414 if (flags & F_STDERR) 415 (void) dup(1); 416 else 417 (void) dup(SHDIAG); 418 didfds = 1; 419 } 420 421 mypipe(pv) 422 register int *pv; 423 { 424 425 if (pipe(pv) < 0) 426 goto oops; 427 pv[0] = dmove(pv[0], -1); 428 pv[1] = dmove(pv[1], -1); 429 if (pv[0] >= 0 && pv[1] >= 0) 430 return; 431 oops: 432 error("Can't make pipe"); 433 } 434 435 chkclob(cp) 436 register char *cp; 437 { 438 struct stat stb; 439 440 if (stat(cp, &stb) < 0) 441 return; 442 if ((stb.st_mode & S_IFMT) == S_IFCHR) 443 return; 444 error("%s: File exists", cp); 445 } 446