void
restfd(int fd, int ofd)
{
if (fd == 2)
shf_flush(&shf_iob[fd]);
if (ofd < 0) /* original fd closed */
close(fd);
else if (fd != ofd) {
ksh_dup2(ofd, fd, true); /* XXX: what to do if this fails? */
close(ofd);
}
}
/*
* execute command tree
*/
int
execute(struct op * volatile t,
/* if XEXEC don't fork */
volatile int flags,
volatile int * volatile xerrok)
{
int i;
volatile int rv = 0, dummy = 0;
int pv[2];
const char ** volatile ap = NULL;
char ** volatile up;
const char *s, *ccp;
struct ioword **iowp;
struct tbl *tp = NULL;
char *cp;
if (t == NULL)
return (0);
/* Caller doesn't care if XERROK should propagate. */
if (xerrok == NULL)
xerrok = &dummy;
if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
/* run in sub-process */
return (exchild(t, flags & ~XTIME, xerrok, -1));
newenv(E_EXEC);
if (trap)
runtraps(0);
/* we want to run an executable, do some variance checks */
if (t->type == TCOM) {
/* check if this is 'var=<<EOF' */
if (
/* we have zero arguments, i.e. no programme to run */
t->args[0] == NULL &&
/* we have exactly one variable assignment */
t->vars[0] != NULL && t->vars[1] == NULL &&
/* we have exactly one I/O redirection */
t->ioact != NULL && t->ioact[0] != NULL &&
t->ioact[1] == NULL &&
/* of type "here document" (or "here string") */
(t->ioact[0]->flag & IOTYPE) == IOHERE &&
/* the variable assignment begins with a valid varname */
(ccp = skip_wdvarname(t->vars[0], true)) != t->vars[0] &&
/* and has no right-hand side (i.e. "varname=") */
ccp[0] == CHAR && ccp[1] == '=' && ccp[2] == EOS &&
/* plus we can have a here document content */
herein(t->ioact[0], &cp) == 0 && cp && *cp) {
char *sp = cp, *dp;
size_t n = ccp - t->vars[0] + 2, z;
/* drop redirection (will be garbage collected) */
t->ioact = NULL;
/* set variable to its expanded value */
z = strlen(cp) + 1;
if (notoktomul(z, 2) || notoktoadd(z * 2, n))
internal_errorf(Toomem, (unsigned long)-1);
dp = alloc(z * 2 + n, ATEMP);
memcpy(dp, t->vars[0], n);
t->vars[0] = dp;
dp += n;
while (*sp) {
*dp++ = QCHAR;
*dp++ = *sp++;
}
*dp = EOS;
/* free the expanded value */
afree(cp, APERM);
}
/*
* Clear subst_exstat before argument expansion. Used by
* null commands (see comexec() and c_eval()) and by c_set().
*/
subst_exstat = 0;
/* for $LINENO */
current_lineno = t->lineno;
/*
* POSIX says expand command words first, then redirections,
* and assignments last..
*/
up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
if (flags & XTIME)
/* Allow option parsing (bizarre, but POSIX) */
timex_hook(t, &up);
ap = (const char **)up;
if (Flag(FXTRACE) && ap[0]) {
shf_puts(substitute(str_val(global("PS4")), 0),
shl_out);
for (i = 0; ap[i]; i++)
shf_fprintf(shl_out, "%s%c", ap[i],
ap[i + 1] ? ' ' : '\n');
shf_flush(shl_out);
}
if (ap[0])
tp = findcom(ap[0], FC_BI|FC_FUNC);
}
flags &= ~XTIME;
if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
e->savefd = alloc2(NUFILE, sizeof(short), ATEMP);
/* initialise to not redirected */
memset(e->savefd, 0, NUFILE * sizeof(short));
}
/* mark for replacement later (unless TPIPE) */
vp_pipest->flag |= INT_L;
/* do redirection, to be restored in quitenv() */
if (t->ioact != NULL)
for (iowp = t->ioact; *iowp != NULL; iowp++) {
if (iosetup(*iowp, tp) < 0) {
exstat = rv = 1;
/*
* Redirection failures for special commands
* cause (non-interactive) shell to exit.
*/
if (tp && tp->type == CSHELL &&
(tp->flag & SPEC_BI))
errorfz();
/* Deal with FERREXIT, quitenv(), etc. */
goto Break;
}
}
switch (t->type) {
case TCOM:
rv = comexec(t, tp, (const char **)ap, flags, xerrok);
break;
case TPAREN:
rv = execute(t->left, flags | XFORK, xerrok);
break;
case TPIPE:
flags |= XFORK;
flags &= ~XEXEC;
e->savefd[0] = savefd(0);
e->savefd[1] = savefd(1);
while (t->type == TPIPE) {
openpipe(pv);
/* stdout of curr */
ksh_dup2(pv[1], 1, false);
/**
* Let exchild() close pv[0] in child
* (if this isn't done, commands like
* (: ; cat /etc/termcap) | sleep 1
* will hang forever).
*/
exchild(t->left, flags | XPIPEO | XCCLOSE,
NULL, pv[0]);
/* stdin of next */
ksh_dup2(pv[0], 0, false);
closepipe(pv);
flags |= XPIPEI;
t = t->right;
}
/* stdout of last */
restfd(1, e->savefd[1]);
/* no need to re-restore this */
e->savefd[1] = 0;
/* Let exchild() close 0 in parent, after fork, before wait */
i = exchild(t, flags | XPCLOSE | XPIPEST, xerrok, 0);
if (!(flags&XBGND) && !(flags&XXCOM))
rv = i;
break;
case TLIST:
while (t->type == TLIST) {
execute(t->left, flags & XERROK, NULL);
t = t->right;
}
rv = execute(t, flags & XERROK, xerrok);
break;
case TCOPROC: {
#ifndef MKSH_NOPROSPECTOFWORK
sigset_t omask;
/*
* Block sigchild as we are using things changed in the
* signal handler
*/
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
e->type = E_ERRH;
if ((i = kshsetjmp(e->jbuf))) {
sigprocmask(SIG_SETMASK, &omask, NULL);
quitenv(NULL);
unwind(i);
/* NOTREACHED */
}
#endif
/* Already have a (live) co-process? */
if (coproc.job && coproc.write >= 0)
errorf("coprocess already exists");
/* Can we re-use the existing co-process pipe? */
coproc_cleanup(true);
/* do this before opening pipes, in case these fail */
e->savefd[0] = savefd(0);
e->savefd[1] = savefd(1);
openpipe(pv);
if (pv[0] != 0) {
ksh_dup2(pv[0], 0, false);
close(pv[0]);
}
coproc.write = pv[1];
coproc.job = NULL;
if (coproc.readw >= 0)
ksh_dup2(coproc.readw, 1, false);
else {
openpipe(pv);
coproc.read = pv[0];
ksh_dup2(pv[1], 1, false);
/* closed before first read */
coproc.readw = pv[1];
coproc.njobs = 0;
/* create new coprocess id */
++coproc.id;
}
#ifndef MKSH_NOPROSPECTOFWORK
sigprocmask(SIG_SETMASK, &omask, NULL);
/* no more need for error handler */
e->type = E_EXEC;
#endif
/*
* exchild() closes coproc.* in child after fork,
* will also increment coproc.njobs when the
* job is actually created.
*/
flags &= ~XEXEC;
exchild(t->left, flags | XBGND | XFORK | XCOPROC | XCCLOSE,
NULL, coproc.readw);
break;
}
case TASYNC:
/*
* XXX non-optimal, I think - "(foo &)", forks for (),
* forks again for async... parent should optimise
* this to "foo &"...
*/
rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK, xerrok);
break;
case TOR:
case TAND:
rv = execute(t->left, XERROK, xerrok);
if ((rv == 0) == (t->type == TAND))
rv = execute(t->right, XERROK, xerrok);
flags |= XERROK;
if (xerrok)
*xerrok = 1;
break;
case TBANG:
rv = !execute(t->right, XERROK, xerrok);
flags |= XERROK;
if (xerrok)
*xerrok = 1;
break;
case TDBRACKET: {
Test_env te;
te.flags = TEF_DBRACKET;
te.pos.wp = t->args;
te.isa = dbteste_isa;
te.getopnd = dbteste_getopnd;
te.eval = test_eval;
te.error = dbteste_error;
rv = test_parse(&te);
break;
}
case TFOR:
case TSELECT: {
volatile bool is_first = true;
ap = (t->vars == NULL) ? e->loc->argv + 1 :
(const char **)eval((const char **)t->vars,
DOBLANK | DOGLOB | DOTILDE);
e->type = E_LOOP;
while ((i = kshsetjmp(e->jbuf))) {
if ((e->flags&EF_BRKCONT_PASS) ||
(i != LBREAK && i != LCONTIN)) {
quitenv(NULL);
unwind(i);
} else if (i == LBREAK) {
rv = 0;
goto Break;
}
}
/* in case of a continue */
rv = 0;
if (t->type == TFOR) {
while (*ap != NULL) {
setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
rv = execute(t->left, flags & XERROK, xerrok);
}
} else {
/* TSELECT */
for (;;) {
if (!(ccp = do_selectargs(ap, is_first))) {
rv = 1;
break;
}
is_first = false;
setstr(global(t->str), ccp, KSH_UNWIND_ERROR);
execute(t->left, flags & XERROK, xerrok);
}
}
break;
}
case TWHILE:
case TUNTIL:
e->type = E_LOOP;
while ((i = kshsetjmp(e->jbuf))) {
if ((e->flags&EF_BRKCONT_PASS) ||
(i != LBREAK && i != LCONTIN)) {
quitenv(NULL);
unwind(i);
} else if (i == LBREAK) {
rv = 0;
goto Break;
}
}
/* in case of a continue */
rv = 0;
while ((execute(t->left, XERROK, NULL) == 0) ==
(t->type == TWHILE))
rv = execute(t->right, flags & XERROK, xerrok);
break;
case TIF:
case TELIF:
if (t->right == NULL)
/* should be error */
break;
rv = execute(t->left, XERROK, NULL) == 0 ?
execute(t->right->left, flags & XERROK, xerrok) :
execute(t->right->right, flags & XERROK, xerrok);
break;
case TCASE:
i = 0;
ccp = evalstr(t->str, DOTILDE);
for (t = t->left; t != NULL && t->type == TPAT; t = t->right) {
for (ap = (const char **)t->vars; *ap; ap++) {
if (i || ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
gmatchx(ccp, s, false))) {
rv = execute(t->left, flags & XERROK,
xerrok);
i = 0;
switch (t->u.charflag) {
case '&':
i = 1;
/* FALLTHROUGH */
case '|':
goto TCASE_next;
}
goto TCASE_out;
}
}
i = 0;
TCASE_next:
/* empty */;
}
TCASE_out:
break;
case TBRACE:
rv = execute(t->left, flags & XERROK, xerrok);
break;
case TFUNCT:
rv = define(t->str, t);
break;
case TTIME:
/*
* Clear XEXEC so nested execute() call doesn't exit
* (allows "ls -l | time grep foo").
*/
rv = timex(t, flags & ~XEXEC, xerrok);
break;
case TEXEC:
/* an eval'd TCOM */
s = t->args[0];
up = makenv();
restoresigs();
cleanup_proc_env();
{
union mksh_ccphack cargs;
cargs.ro = t->args;
execve(t->str, cargs.rw, up);
rv = errno;
}
if (rv == ENOEXEC)
scriptexec(t, (const char **)up);
else
errorf("%s: %s", s, cstrerror(rv));
}
Break:
exstat = rv & 0xFF;
if (vp_pipest->flag & INT_L) {
unset(vp_pipest, 1);
vp_pipest->flag = DEFINED | ISSET | INTEGER | RDONLY |
ARRAY | INT_U;
vp_pipest->val.i = rv;
}
/* restores IO */
quitenv(NULL);
if ((flags&XEXEC))
/* exit child */
unwind(LEXIT);
if (rv != 0 && !(flags & XERROK) &&
(xerrok == NULL || !*xerrok)) {
if (Flag(FERREXIT) & 0x80) {
/* inside eval */
Flag(FERREXIT) = 0;
} else {
trapsig(ksh_SIGERR);
if (Flag(FERREXIT))
unwind(LERROR);
}
}
return (rv);
}
/*
* set up redirection, saving old fds in e->savefd
*/
static int
iosetup(struct ioword *iop, struct tbl *tp)
{
int u = -1;
char *cp = iop->name;
int iotype = iop->flag & IOTYPE;
bool do_open = true, do_close = false;
int flags = 0;
struct ioword iotmp;
struct stat statb;
if (iotype != IOHERE)
cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
/* Used for tracing and error messages to print expanded cp */
iotmp = *iop;
iotmp.name = (iotype == IOHERE) ? NULL : cp;
iotmp.flag |= IONAMEXP;
if (Flag(FXTRACE))
shellf("%s%s\n",
substitute(str_val(global("PS4")), 0),
snptreef(NULL, 32, "%R", &iotmp));
switch (iotype) {
case IOREAD:
flags = O_RDONLY;
break;
case IOCAT:
flags = O_WRONLY | O_APPEND | O_CREAT;
break;
case IOWRITE:
flags = O_WRONLY | O_CREAT | O_TRUNC;
/*
* The stat() is here to allow redirections to
* things like /dev/null without error.
*/
if (Flag(FNOCLOBBER) && !(iop->flag & IOCLOB) &&
(stat(cp, &statb) < 0 || S_ISREG(statb.st_mode)))
flags |= O_EXCL;
break;
case IORDWR:
flags = O_RDWR | O_CREAT;
break;
case IOHERE:
do_open = false;
/* herein() returns -2 if error has been printed */
u = herein(iop, NULL);
/* cp may have wrong name */
break;
case IODUP: {
const char *emsg;
do_open = false;
if (*cp == '-' && !cp[1]) {
/* prevent error return below */
u = 1009;
do_close = true;
} else if ((u = check_fd(cp,
X_OK | ((iop->flag & IORDUP) ? R_OK : W_OK),
&emsg)) < 0) {
warningf(true, "%s: %s",
snptreef(NULL, 32, "%R", &iotmp), emsg);
return (-1);
}
if (u == iop->unit)
/* "dup from" == "dup to" */
return (0);
break;
}
}
if (do_open) {
if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
warningf(true, "%s: %s", cp, "restricted");
return (-1);
}
u = open(cp, flags, 0666);
}
if (u < 0) {
/* herein() may already have printed message */
if (u == -1) {
u = errno;
warningf(true, "can't %s %s: %s",
iotype == IODUP ? "dup" :
(iotype == IOREAD || iotype == IOHERE) ?
"open" : "create", cp, cstrerror(u));
}
return (-1);
}
/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
if (e->savefd[iop->unit] == 0) {
/* If these are the same, it means unit was previously closed */
if (u == iop->unit)
e->savefd[iop->unit] = -1;
else
/*
* c_exec() assumes e->savefd[fd] set for any
* redirections. Ask savefd() not to close iop->unit;
* this allows error messages to be seen if iop->unit
* is 2; also means we can't lose the fd (eg, both
* dup2 below and dup2 in restfd() failing).
*/
e->savefd[iop->unit] = savefd(iop->unit);
}
if (do_close)
close(iop->unit);
else if (u != iop->unit) {
if (ksh_dup2(u, iop->unit, true) < 0) {
int eno;
eno = errno;
warningf(true, "%s %s %s",
"can't finish (dup) redirection",
snptreef(NULL, 32, "%R", &iotmp),
cstrerror(eno));
if (iotype != IODUP)
close(u);
return (-1);
}
if (iotype != IODUP)
close(u);
/*
* Touching any co-process fd in an empty exec
* causes the shell to close its copies
*/
else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
if (iop->flag & IORDUP)
/* possible exec <&p */
coproc_read_close(u);
else
/* possible exec >&p */
coproc_write_close(u);
}
}
if (u == 2)
/* Clear any write errors */
shf_reopen(2, SHF_WR, shl_out);
return (0);
}
/* execute tree in child subprocess */
int
exchild(struct op *t, int flags, volatile int *xerrok,
int close_fd) /* used if XPCLOSE or XCCLOSE */
{
static Proc *last_proc; /* for pipelines */
int i;
sigset_t omask;
Proc *p;
Job *j;
int rv = 0;
int forksleep;
int ischild;
if (flags & XEXEC)
/* Clear XFORK|XPCLOSE|XCCLOSE|XCOPROC|XPIPEO|XPIPEI|XXCOM|XBGND
* (also done in another execute() below)
*/
return execute(t, flags & (XEXEC | XERROK), xerrok);
/* no SIGCHLD's while messing with job and process lists */
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
p = new_proc();
p->next = (Proc *) 0;
p->state = PRUNNING;
p->status = 0;
p->pid = 0;
/* link process into jobs list */
if (flags&XPIPEI) { /* continuing with a pipe */
if (!last_job)
internal_errorf(1,
"exchild: XPIPEI and no last_job - pid %d",
(int) procpid);
j = last_job;
last_proc->next = p;
last_proc = p;
} else {
j = new_job(); /* fills in j->job */
/* we don't consider XXCOM's foreground since they don't get
* tty process group and we don't save or restore tty modes.
*/
j->flags = (flags & XXCOM) ? JF_XXCOM :
((flags & XBGND) ? 0 : (JF_FG|JF_USETTYMODE));
timerclear(&j->usrtime);
timerclear(&j->systime);
j->state = PRUNNING;
j->pgrp = 0;
j->ppid = procpid;
j->age = ++njobs;
j->proc_list = p;
j->coproc_id = 0;
last_job = j;
last_proc = p;
put_job(j, PJ_PAST_STOPPED);
}
snptreef(p->command, sizeof(p->command), "%T", t);
/* create child process */
forksleep = 1;
while ((i = fork()) < 0 && errno == EAGAIN && forksleep < 32) {
if (intrsig) /* allow user to ^C out... */
break;
sleep(forksleep);
forksleep <<= 1;
}
if (i < 0) {
kill_job(j, SIGKILL);
remove_job(j, "fork failed");
sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
errorf("cannot fork - try again");
}
ischild = i == 0;
if (ischild)
p->pid = procpid = getpid();
else
p->pid = i;
#ifdef JOBS
/* job control set up */
if (Flag(FMONITOR) && !(flags&XXCOM)) {
int dotty = 0;
if (j->pgrp == 0) { /* First process */
j->pgrp = p->pid;
dotty = 1;
}
/* set pgrp in both parent and child to deal with race
* condition
*/
setpgid(p->pid, j->pgrp);
/* YYY: should this be
if (ttypgrp_ok && ischild && !(flags&XBGND))
tcsetpgrp(tty_fd, j->pgrp);
instead? (see also YYY below)
*/
if (ttypgrp_ok && dotty && !(flags & XBGND))
tcsetpgrp(tty_fd, j->pgrp);
}
#endif /* JOBS */
/* used to close pipe input fd */
if (close_fd >= 0 && (((flags & XPCLOSE) && !ischild) ||
((flags & XCCLOSE) && ischild)))
close(close_fd);
if (ischild) { /* child */
/* Do this before restoring signal */
if (flags & XCOPROC)
coproc_cleanup(false);
sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
cleanup_parents_env();
#ifdef JOBS
/* If FMONITOR or FTALKING is set, these signals are ignored,
* if neither FMONITOR nor FTALKING are set, the signals have
* their inherited values.
*/
if (Flag(FMONITOR) && !(flags & XXCOM)) {
for (i = NELEM(tt_sigs); --i >= 0; )
setsig(&sigtraps[tt_sigs[i]], SIG_DFL,
SS_RESTORE_DFL|SS_FORCE);
}
#endif /* JOBS */
if (Flag(FBGNICE) && (flags & XBGND))
nice(4);
if ((flags & XBGND) && !Flag(FMONITOR)) {
setsig(&sigtraps[SIGINT], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
setsig(&sigtraps[SIGQUIT], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
if (!(flags & (XPIPEI | XCOPROC))) {
int fd = open("/dev/null", 0);
if (fd != 0) {
(void) ksh_dup2(fd, 0, true);
close(fd);
}
}
}
remove_job(j, "child"); /* in case of `jobs` command */
nzombie = 0;
#ifdef JOBS
ttypgrp_ok = 0;
Flag(FMONITOR) = 0;
#endif /* JOBS */
Flag(FTALKING) = 0;
tty_close();
cleartraps();
execute(t, (flags & XERROK) | XEXEC, NULL); /* no return */
internal_errorf(0, "exchild: execute() returned");
unwind(LLEAVE);
/* NOTREACHED */
}
/* shell (parent) stuff */
/* Ensure next child gets a (slightly) different $RANDOM sequence */
change_random();
if (!(flags & XPIPEO)) { /* last process in a job */
#ifdef JOBS
/* YYY: Is this needed? (see also YYY above)
if (Flag(FMONITOR) && !(flags&(XXCOM|XBGND)))
tcsetpgrp(tty_fd, j->pgrp);
*/
#endif /* JOBS */
j_startjob(j);
if (flags & XCOPROC) {
j->coproc_id = coproc.id;
coproc.njobs++; /* n jobs using co-process output */
coproc.job = (void *) j; /* j using co-process input */
}
if (flags & XBGND) {
j_set_async(j);
if (Flag(FTALKING)) {
shf_fprintf(shl_out, "[%d]", j->job);
for (p = j->proc_list; p; p = p->next)
shf_fprintf(shl_out, " %d", p->pid);
shf_putchar('\n', shl_out);
shf_flush(shl_out);
}
} else
rv = j_waitj(j, JW_NONE, "jw:last proc");
}
sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
return rv;
}
int
exchild(struct op *t, int flags,
int close_fd) /* used if XPCLOSE or XCCLOSE */
{
static Proc *last_proc; /* for pipelines */
int i;
sigset_t omask;
Proc *p;
Job *j;
int rv = 0;
int forksleep;
int ischild;
if (flags & XEXEC)
/* Clear XFORK|XPCLOSE|XCCLOSE|XCOPROC|XPIPEO|XPIPEI|XXCOM|XBGND
* (also done in another execute() below)
*/
return execute(t, flags & (XEXEC | XERROK));
p = new_proc();
p->next = (Proc *) 0;
p->state = PRUNNING;
p->status = 0;
p->pid = 0;
/* link process into jobs list */
if (flags&XPIPEI) { /* continuing with a pipe */
if (!last_job)
internal_errorf(1,
"exchild: XPIPEI and no last_job - pid %d",
(int) procpid);
j = last_job;
last_proc->next = p;
last_proc = p;
} else {
j = new_job(); /* fills in j->job */
/* we don't consider XXCOM's foreground since they don't get
* tty process group and we don't save or restore tty modes.
*/
j->flags = (flags & XXCOM) ? JF_XXCOM :
((flags & XBGND) ? 0 : (JF_FG|JF_USETTYMODE));
j->usrtime = j->systime = 0;
j->state = PRUNNING;
j->pgrp = 0;
j->ppid = procpid;
j->age = ++njobs;
j->proc_list = p;
j->coproc_id = 0;
last_job = j;
last_proc = p;
put_job(j, PJ_PAST_STOPPED);
}
snptreef(p->command, sizeof(p->command), "%T", t);
/* create child process */
forksleep = 1;
while ((i = fork()) < 0 && errno == EAGAIN && forksleep < 32) {
if (intrsig) /* allow user to ^C out... */
break;
sleep(forksleep);
forksleep <<= 1;
}
if (i < 0) {
kill_job(j, SIGKILL);
remove_job(j, "fork failed");
sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
errorf("cannot fork - try again");
}
ischild = i == 0;
if (ischild)
p->pid = procpid = getpid();
else
p->pid = i;
/* used to close pipe input fd */
if (close_fd >= 0 && (((flags & XPCLOSE) && !ischild) ||
((flags & XCCLOSE) && ischild)))
close(close_fd);
if (ischild) { /* child */
/* Do this before restoring signal */
if (flags & XCOPROC)
coproc_cleanup(false);
sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
cleanup_parents_env();
if ((flags & XBGND)) {
setsig(&sigtraps[SIGINT], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
setsig(&sigtraps[SIGQUIT], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
if (!(flags & (XPIPEI | XCOPROC))) {
int fd = open("/dev/null", 0);
if (fd != 0) {
(void) ksh_dup2(fd, 0, true);
close(fd);
}
}
}
remove_job(j, "child"); /* in case of `jobs` command */
nzombie = 0;
Flag(FTALKING) = 0;
tty_close();
cleartraps();
execute(t, (flags & XERROK) | XEXEC); /* no return */
internal_errorf(0, "exchild: execute() returned");
unwind(LLEAVE);
/* NOTREACHED */
}
/* shell (parent) stuff */
/* Ensure next child gets a (slightly) different $RANDOM sequence */
change_random();
if (!(flags & XPIPEO)) { /* last process in a job */
j_startjob(j);
if (flags & XCOPROC) {
j->coproc_id = coproc.id;
coproc.njobs++; /* n jobs using co-process output */
coproc.job = (void *) j; /* j using co-process input */
}
if (flags & XBGND) {
j_set_async(j);
if (Flag(FTALKING)) {
shf_fprintf(shl_out, "[%d]", j->job);
for (p = j->proc_list; p; p = p->next)
shf_fprintf(shl_out, " %d", p->pid);
shf_putchar('\n', shl_out);
shf_flush(shl_out);
}
} else
rv = j_waitj(j, JW_NONE, "jw:last proc");
}
sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
return rv;
}
static void
chvt(const char *fn)
{
char dv[20];
struct stat sb;
int fd;
/* for entropy */
kshstate_f.h = evilhash(fn);
if (*fn == '-') {
memcpy(dv, "-/dev/null", sizeof("-/dev/null"));
fn = dv + 1;
} else {
if (stat(fn, &sb)) {
memcpy(dv, "/dev/ttyC", 9);
strlcpy(dv + 9, fn, sizeof(dv) - 9);
if (stat(dv, &sb)) {
strlcpy(dv + 8, fn, sizeof(dv) - 8);
if (stat(dv, &sb))
errorf("chvt: can't find tty %s", fn);
}
fn = dv;
}
if (!(sb.st_mode & S_IFCHR))
errorf("chvt: not a char device: %s", fn);
if ((sb.st_uid != 0) && chown(fn, 0, 0))
warningf(false, "chvt: cannot chown root %s", fn);
if (((sb.st_mode & 07777) != 0600) && chmod(fn, (mode_t)0600))
warningf(false, "chvt: cannot chmod 0600 %s", fn);
#if HAVE_REVOKE
if (revoke(fn))
#endif
warningf(false, "chvt: cannot revoke %s, new shell is"
" potentially insecure", fn);
}
if ((fd = open(fn, O_RDWR)) == -1) {
sleep(1);
if ((fd = open(fn, O_RDWR)) == -1)
errorf("chvt: cannot open %s", fn);
}
switch (fork()) {
case -1:
errorf("chvt: %s failed", "fork");
case 0:
break;
default:
exit(0);
}
if (setsid() == -1)
errorf("chvt: %s failed", "setsid");
if (fn != dv + 1) {
if (ioctl(fd, TIOCSCTTY, NULL) == -1)
errorf("chvt: %s failed", "TIOCSCTTY");
if (tcflush(fd, TCIOFLUSH))
errorf("chvt: %s failed", "TCIOFLUSH");
}
ksh_dup2(fd, 0, false);
ksh_dup2(fd, 1, false);
ksh_dup2(fd, 2, false);
if (fd > 2)
close(fd);
chvt_reinit();
}
static void
chvt(const Getopt *go)
{
const char *dv = go->optarg;
char *cp = NULL;
int fd;
switch (*dv) {
case '-':
dv = "/dev/null";
break;
case '!':
++dv;
/* FALLTHROUGH */
default: {
struct stat sb;
if (stat(dv, &sb)) {
cp = shf_smprintf("/dev/ttyC%s", dv);
dv = cp;
if (stat(dv, &sb)) {
memmove(cp + 1, cp, /* /dev/tty */ 8);
dv = cp + 1;
if (stat(dv, &sb)) {
errorf("%s: %s: %s", "chvt",
"can't find tty", go->optarg);
}
}
}
if (!(sb.st_mode & S_IFCHR))
errorf("%s: %s: %s", "chvt", "not a char device", dv);
#ifndef MKSH_DISABLE_REVOKE_WARNING
#if HAVE_REVOKE
if (revoke(dv))
#endif
warningf(false, "%s: %s %s", "chvt",
"new shell is potentially insecure, can't revoke",
dv);
#endif
}
}
if ((fd = binopen2(dv, O_RDWR)) < 0) {
sleep(1);
if ((fd = binopen2(dv, O_RDWR)) < 0) {
errorf("%s: %s %s", "chvt", "can't open", dv);
}
}
if (go->optarg[0] != '!') {
switch (fork()) {
case -1:
errorf("%s: %s %s", "chvt", "fork", "failed");
case 0:
break;
default:
exit(0);
}
}
if (setsid() == -1)
errorf("%s: %s %s", "chvt", "setsid", "failed");
if (go->optarg[0] != '-') {
if (ioctl(fd, TIOCSCTTY, NULL) == -1)
errorf("%s: %s %s", "chvt", "TIOCSCTTY", "failed");
if (tcflush(fd, TCIOFLUSH))
errorf("%s: %s %s", "chvt", "TCIOFLUSH", "failed");
}
ksh_dup2(fd, 0, false);
ksh_dup2(fd, 1, false);
ksh_dup2(fd, 2, false);
if (fd > 2)
close(fd);
rndset((unsigned long)chvt_rndsetup(go, sizeof(Getopt)));
chvt_reinit();
}
