/*
* execute command tree
*/
int
execute(struct op *volatile t,
volatile int flags, volatile int *xerrok) /* if XEXEC don't fork */
{
int i, dummy = 0;
volatile int rv = 0;
int pv[2];
char ** volatile ap;
char *s, *cp;
struct ioword **iowp;
struct tbl *tp = NULL;
if (t == NULL)
return 0;
/* Caller doesn't care if XERROK should propagate. */
if (xerrok == NULL)
xerrok = &dummy;
/* Is this the end of a pipeline? If so, we want to evaluate the
* command arguments
bool eval_done = false;
if ((flags&XFORK) && !(flags&XEXEC) && (flags&XPCLOSE)) {
eval_done = true;
tp = eval_execute_args(t, &ap);
}
*/
if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
return exchild(t, flags & ~XTIME, xerrok, -1); /* run in sub-process */
newenv(E_EXEC);
if (trap)
runtraps(0);
if (t->type == TCOM) {
/* Clear subst_exstat before argument expansion. Used by
* null commands (see comexec() and c_eval()) and by c_set().
*/
subst_exstat = 0;
current_lineno = t->lineno; /* for $LINENO */
/* POSIX says expand command words first, then redirections,
* and assignments last..
*/
ap = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
if (flags & XTIME)
/* Allow option parsing (bizarre, but POSIX) */
timex_hook(t, &ap);
if (Flag(FXTRACE) && ap[0]) {
shf_fprintf(shl_out, "%s",
PS4_SUBSTITUTE(str_val(global("PS4"))));
for (i = 0; ap[i]; i++)
shf_fprintf(shl_out, "%s%s", ap[i],
ap[i + 1] ? space : newline);
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 = (short *) alloc(sizeofN(short, NUFILE), ATEMP);
/* initialize to not redirected */
memset(e->savefd, 0, sizeofN(short, NUFILE));
}
/*
* run the commands from the input source, returning status.
*/
int
shell(Source * volatile s, volatile int level)
{
struct op *t;
volatile bool wastty = tobool(s->flags & SF_TTY);
volatile uint8_t attempts = 13;
volatile bool interactive = (level == 0) && Flag(FTALKING);
volatile bool sfirst = true;
Source *volatile old_source = source;
int i;
newenv(level == 2 ? E_EVAL : E_PARSE);
if (interactive)
really_exit = false;
switch ((i = kshsetjmp(e->jbuf))) {
case 0:
break;
case LBREAK:
case LCONTIN:
if (level != 2) {
source = old_source;
quitenv(NULL);
internal_errorf(Tf_cant_s, Tshell,
i == LBREAK ? Tbreak : Tcontinue);
/* NOTREACHED */
}
/* assert: interactive == false */
/* FALLTHROUGH */
case LINTR:
/* we get here if SIGINT not caught or ignored */
case LERROR:
case LSHELL:
if (interactive) {
if (i == LINTR)
shellf("\n");
/*
* Reset any eof that was read as part of a
* multiline command.
*/
if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
s->type = SSTDIN;
/*
* Used by exit command to get back to
* top level shell. Kind of strange since
* interactive is set if we are reading from
* a tty, but to have stopped jobs, one only
* needs FMONITOR set (not FTALKING/SF_TTY)...
*/
/* toss any input we have so far */
yyrecursive_pop(true);
s->start = s->str = null;
retrace_info = NULL;
herep = heres;
break;
}
/* FALLTHROUGH */
case LEXIT:
case LLEAVE:
case LRETURN:
source = old_source;
quitenv(NULL);
/* keep on going */
unwind(i);
/* NOTREACHED */
default:
source = old_source;
quitenv(NULL);
internal_errorf(Tunexpected_type, Tunwind, Tshell, i);
/* NOTREACHED */
}
while (/* CONSTCOND */ 1) {
if (trap)
runtraps(0);
if (s->next == NULL) {
if (Flag(FVERBOSE))
s->flags |= SF_ECHO;
else
s->flags &= ~SF_ECHO;
}
if (interactive) {
j_notify();
set_prompt(PS1, s);
}
t = compile(s, sfirst, true);
if (interactive)
histsave(&s->line, NULL, HIST_FLUSH, true);
sfirst = false;
if (!t)
goto source_no_tree;
if (t->type == TEOF) {
if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
shellf("Use 'exit' to leave mksh\n");
s->type = SSTDIN;
} else if (wastty && !really_exit &&
j_stopped_running()) {
really_exit = true;
s->type = SSTDIN;
} else {
/*
* this for POSIX which says EXIT traps
* shall be taken in the environment
* immediately after the last command
* executed.
*/
if (level == 0)
unwind(LEXIT);
break;
}
} else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
t->u.evalflags |= DOTCOMEXEC;
if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
exstat = execute(t, 0, NULL) & 0xFF;
if (t->type != TEOF && interactive && really_exit)
really_exit = false;
source_no_tree:
reclaim();
}
quitenv(NULL);
source = old_source;
return (exstat & 0xFF);
}
cell proc_eval(const cell &x)
{
bool listvars = false;
if (listvars)
proc_listvars(cell());
if (x.type == v_string || x.type == v_number || x.type == v_function)
return x;
else if (x.type == v_symbol)
{
//std::cout << "fetching var " << x.str << ": " << toString(env->get(x.str)) << "\n";
return env->get(x.str);
}
else if (x.type == v_list)
{
if (!x.car)
return nil;
cell head = proc_eval(*x.car);
if (head.type == v_proc)
return head.proc(x.cdr? *x.cdr : nil);
if (head.type == v_function)
{
std::shared_ptr<environment> oldenv = env;
std::shared_ptr<environment> newenv(new environment(head.env));
const cell *name_iter = head.car;
const cell *arg_iter = x.cdr;
while (arg_iter && arg_iter->car && name_iter && name_iter->car)
{
if (name_iter->car->str == "&REST")
{
if (!(name_iter->cdr && name_iter->cdr->car && name_iter->cdr->car->type == v_symbol))
throw(exception("Error: expected name for &rest parameter"));
cell head(v_list);
cell *tail = &head;
while (arg_iter && arg_iter->car)
{
tail->car = new cell();
*tail->car = proc_eval(*arg_iter->car);
tail->cdr = new cell(v_list);
tail = tail->cdr;
arg_iter = arg_iter->cdr;
}
newenv->vars[name_iter->cdr->car->str] = head;
name_iter = name_iter->cdr->cdr;
break; //skip the outer loop so we don't dereference the null car pointer.
}
newenv->vars[name_iter->car->str] = proc_eval(*arg_iter->car);
arg_iter = arg_iter->cdr;
name_iter = name_iter->cdr;
}
if (arg_iter && arg_iter->car)
throw(exception("Error: too many arguments to function"));
if (name_iter && name_iter->car)
throw(exception("Error: too few arguments to function"));
env = newenv;
cell result;
cell *body_iter = head.cdr;
while (body_iter && body_iter->car)
{
result = proc_eval(*body_iter->car);
body_iter = body_iter->cdr;
}
env = oldenv;
return result;
}
if (head.type == v_macro)
return proc_eval(expand_macro(head, x.cdr? *x.cdr : cell(v_list)));
throw(exception("Error: attempt to call non-proc"));
}
else
{
throw(exception("Unrecognised cell type! (eval)"));
}
}
int
include(const char *name, int argc, const char **argv, bool intr_ok)
{
Source *volatile s = NULL;
struct shf *shf;
const char **volatile old_argv;
volatile int old_argc;
int i;
shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
if (shf == NULL)
return (-1);
if (argv) {
old_argv = e->loc->argv;
old_argc = e->loc->argc;
} else {
old_argv = NULL;
old_argc = 0;
}
newenv(E_INCL);
if ((i = kshsetjmp(e->jbuf))) {
quitenv(s ? s->u.shf : NULL);
if (old_argv) {
e->loc->argv = old_argv;
e->loc->argc = old_argc;
}
switch (i) {
case LRETURN:
case LERROR:
/* see below */
return (exstat & 0xFF);
case LINTR:
/*
* intr_ok is set if we are including .profile or $ENV.
* If user ^Cs out, we don't want to kill the shell...
*/
if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
return (1);
/* FALLTHROUGH */
case LEXIT:
case LLEAVE:
case LSHELL:
unwind(i);
/* NOTREACHED */
default:
internal_errorf(Tunexpected_type, Tunwind, Tsource, i);
/* NOTREACHED */
}
}
if (argv) {
e->loc->argv = argv;
e->loc->argc = argc;
}
s = pushs(SFILE, ATEMP);
s->u.shf = shf;
strdupx(s->file, name, ATEMP);
i = shell(s, 1);
quitenv(s->u.shf);
if (old_argv) {
e->loc->argv = old_argv;
e->loc->argc = old_argc;
}
/* & 0xff to ensure value not -1 */
return (i & 0xFF);
}
/*
* 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, (size_t)-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 (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, flags & XERROK, xerrok);
else {
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 | INT_L;
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);
}
