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exec.c
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/* $OpenBSD: exec.c,v 1.52 2015/09/10 22:48:58 nicm Exp $ */
/*-
* Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
* 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018,
* 2019, 2020, 2021, 2022, 2023, 2024, 2025
* mirabilos <m$(date +%Y)@mirbsd.de>
*
* Provided that these terms and disclaimer and all copyright notices
* are retained or reproduced in an accompanying document, permission
* is granted to deal in this work without restriction, including un-
* limited rights to use, publicly perform, distribute, sell, modify,
* merge, give away, or sublicence.
*
* This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
* the utmost extent permitted by applicable law, neither express nor
* implied; without malicious intent or gross negligence. In no event
* may a licensor, author or contributor be held liable for indirect,
* direct, other damage, loss, or other issues arising in any way out
* of dealing in the work, even if advised of the possibility of such
* damage or existence of a defect, except proven that it results out
* of said person's immediate fault when using the work as intended.
*/
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.252 2025/04/27 21:49:18 tg Exp $");
#ifndef MKSH_DEFAULT_EXECSHELL
#define MKSH_DEFAULT_EXECSHELL MKSH_UNIXROOT "/bin/sh"
#endif
static int comexec(struct op *, struct tbl * volatile, const char **,
int volatile, volatile int *);
static void scriptexec(struct op *, const char **) MKSH_A_NORETURN;
static int call_builtin(struct tbl *, const char **, const char *, Wahr);
static int iosetup(struct ioword *, struct tbl *);
static const char *do_selectargs(const char **, Wahr);
static Test_op dbteste_isa(Test_env *, Test_meta);
static const char *dbteste_getopnd(Test_env *, Test_op, Wahr);
static void dbteste_error(Test_env *, int, const char *);
/* XXX: horrible kludge to fit within the framework */
static void plain_fmt_entry(char *, size_t, unsigned int, const void *);
static void select_fmt_entry(char *, size_t, unsigned int, const void *);
/*
* 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;
if (t == NULL)
return (0);
/* Caller doesn't care if XERROK should propagate. */
if (xerrok == NULL)
xerrok = &dummy;
if (flags & XFORK)
switch (t->type) {
case TPIPE:
break;
default:
if (flags & XEXEC)
break;
/* FALLTHROUGH */
case TTIME:
/* 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) {
/*
* 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;
/* check if this is 'var=<<EOF' */
if (
/* we have zero arguments, i.e. no program 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]->ioflag & IOTYPE) == IOHERE &&
/* the variable assignment begins with a valid varname */
(ccp = skip_wdvarname(t->vars[0], Ja)) != t->vars[0] &&
/* and has no right-hand side (i.e. "varname=") */
ccp[0] == CHAR && ((ccp[1] == '=' && ccp[2] == EOS) ||
/* or "varname+=" */ (ccp[1] == '+' && ccp[2] == CHAR &&
ccp[3] == '=' && ccp[4] == EOS))) {
char *cp, *dp;
if ((rv = herein(t->ioact[0], &cp) /*? 1 : 0*/))
cp = NULL;
strdup2x(dp, evalstr(t->vars[0], DOASNTILDE | DOSCALAR),
rv ? null : cp);
typeset(dp, Flag(FEXPORT) ? EXPORT : 0, 0, 0, 0);
/* free the expanded value */
afree(cp, APERM);
afree(dp, ATEMP);
goto Break;
}
/*
* 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->savedfd = alloc2(NUFILE, sizeof(ksh_fdsave), ATEMP);
/* initialise to not redirected */
memset(e->savedfd, 0, NUFILE * sizeof(ksh_fdsave));
}
/* 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))
kerrf(KWF_ERR(1) | KWF_PREFIX |
KWF_FILELINE | KWF_ONEMSG |
KWF_NOERRNO, "redirection failure");
/* 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;
FDSAVE(0, savefd(0));
FDSAVE(1, savefd(1));
while (t->type == TPIPE) {
openpipe(pv);
/* stdout of curr */
ksh_dup2(pv[1], 1, Nee);
/**
* 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, Nee);
closepipe(pv);
flags |= XPIPEI;
t = t->right;
}
/* stdout of last */
restfd(1, SAVEDFD(e, 1));
/* no need to re-restore this */
e->savedfd[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)
kerrf(KWF_ERR(1) | KWF_PREFIX |
KWF_FILELINE | KWF_ONEMSG |
KWF_NOERRNO, "coprocess already exists");
/* Can we re-use the existing co-process pipe? */
coproc_cleanup(Ja);
/* do this before opening pipes, in case these fail */
FDSAVE(0, savefd(0));
FDSAVE(1, savefd(1));
openpipe(pv);
if (pv[0] != 0) {
ksh_dup2(pv[0], 0, Nee);
close(pv[0]);
}
coproc.write = pv[1];
coproc.job = NULL;
if (coproc.readw >= 0)
ksh_dup2(coproc.readw, 1, Nee);
else {
openpipe(pv);
coproc.read = pv[0];
ksh_dup2(pv[1], 1, Nee);
/* 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, NULL);
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 Wahr is_first = Ja;
if (t->vars == NULL)
/* “for i; do” */
ap = cpyargv(NULL, e->loc->argv, ATEMP) + 1;
else
ap = (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 {
do_TSELECT:
if ((ccp = do_selectargs(ap, is_first))) {
is_first = Nee;
setstr(global(t->str), ccp, KSH_UNWIND_ERROR);
execute(t->left, flags & XERROK, xerrok);
goto do_TSELECT;
}
rv = 1;
}
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(execute(t->left, XERROK, NULL) == 0 ?
t->right->left : t->right->right, flags & XERROK, xerrok);
break;
case TCASE:
i = 0;
ccp = evalstr(t->str, DOTILDE | DOSCALAR);
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, Nee))) {
record_match(ccp);
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 */
up = makenv();
restoresigs();
cleanup_proc_env();
/* I/O redirection cleanup to be done in child process */
if (!Flag(FPOSIX) && !Flag(FSH) && t->left->ioact != NULL)
for (iowp = t->left->ioact; *iowp != NULL; iowp++)
if (((*iowp)->ioflag & IODUPSELF) &&
fcntl((*iowp)->unit, F_SETFD, 0) == -1)
kwarnf0(KWF_INTERNAL | KWF_WARNING,
Tcloexec_failed, "clear",
(*iowp)->unit);
/* try to execute */
{
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
kerrf(KWF_VERRNO | KWF_ERR(126) | KWF_PREFIX |
KWF_FILELINE | KWF_ONEMSG, rv, t->str);
}
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)) {
trapsig(ksh_SIGERR);
if (Flag(FERREXIT))
unwind(LERREXT);
}
return (rv);
}
/*
* execute simple command
*/
static int
comexec(struct op *t, struct tbl * volatile tp, const char **ap,
volatile int flags, volatile int *xerrok)
{
int i;
volatile int rv = 0;
const char *cp;
const char **lastp;
int type_flags;
Wahr resetspec;
int fcflags = FC_BI | FC_FUNC | FC_PATH;
struct block *l_expand, *l_assign;
int optc;
const char *exec_argv0 = NULL;
Wahr exec_clrenv = Nee;
volatile kui old_inuse;
const char * volatile old_kshname;
volatile kby old_flags[FNFLAGS];
static struct op texec; /* static for use by child process */
/* snag the last argument for $_ */
if (Flag(FTALKING) && *(lastp = ap)) {
/*
* XXX not the same as AT&T ksh, which only seems to set $_
* after a newline (but not in functions/dot scripts, but in
* interactive and script) - perhaps save last arg here and
* set it in shell()?.
*/
while (*++lastp)
;
/* setstr() can't fail here */
setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
KSH_RETURN_ERROR);
}
/**
* Deal with the shell builtins builtin, exec and command since
* they can be followed by other commands. This must be done before
* we know if we should create a local block which must be done
* before we can do a path search (in case the assignments change
* PATH).
* Odd cases:
* FOO=bar exec >/dev/null FOO is kept but not exported
* FOO=bar exec foobar FOO is exported
* FOO=bar command exec >/dev/null FOO is neither kept nor exported
* FOO=bar command FOO is neither kept nor exported
* PATH=... foobar use new PATH in foobar search
*/
resetspec = Nee;
while (tp && tp->type == CSHELL) {
/* undo effects of command */
fcflags = FC_BI | FC_FUNC | FC_PATH;
if (tp->val.f == c_builtin) {
if ((cp = *++ap) == NULL ||
(!strcmp(cp, "--") && (cp = *++ap) == NULL)) {
tp = NULL;
break;
}
if ((tp = findcom(cp, FC_BI)) == NULL)
kerrf(KWF_ERR(1) | KWF_PREFIX | KWF_FILELINE |
KWF_THREEMSG | KWF_NOERRNO, Tbuiltin, cp,
Tnot_found);
if (tp->type == CSHELL && (tp->flag & LOW_BI))
break;
continue;
} else if (tp->val.f == c_exec) {
if (ap[1] == NULL)
break;
ksh_getopt_reset(&builtin_opt, GF_ERROR);
while ((optc = ksh_getopt(ap, &builtin_opt, "a:c")) != -1)
switch (optc) {
case 'a':
exec_argv0 = builtin_opt.optarg;
break;
case 'c':
exec_clrenv = Ja;
/* ensure we can actually do this */
resetspec = Ja;
break;
default:
rv = 2;
goto Leave;
}
ap += builtin_opt.optind;
flags |= XEXEC;
/* POSuX demands ksh88-like behaviour here */
if (Flag(FPOSIX))
fcflags = FC_PATH;
} else if (tp->val.f == c_command) {
Wahr saw_p = Nee;
/*
* Ugly dealing with options in two places (here
* and in c_command(), but such is life)
*/
ksh_getopt_reset(&builtin_opt, 0);
while ((optc = ksh_getopt(ap, &builtin_opt, ":p")) == 'p')
saw_p = Ja;
if (optc != -1)
/* command -vV or something */
break;
/* don't look for functions */
fcflags = FC_BI | FC_PATH;
if (saw_p) {
if (Flag(FRESTRICTED)) {
kwarnf(KWF_PREFIX | KWF_FILELINE |
KWF_TWOMSG | KWF_NOERRNO,
"command -p", "restricted");
rv = 1;
goto Leave;
}
fcflags |= FC_DEFPATH;
}
ap += builtin_opt.optind;
/*
* POSIX says special builtins lose their status
* if accessed using command.
*/
resetspec = Ja;
if (!ap[0]) {
/* ensure command with no args exits with 0 */
subst_exstat = 0;
break;
}
} else if (tp->flag & LOW_BI) {
/* if we have any flags, do not use the builtin */
if ((ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
/* argument, begins with -, is not - or -- */
(ap[1][1] != '-' || ap[1][2] != '\0')) ||
/* always prefer the external utility */
(tp->flag & LOWER_BI)) {
struct tbl *ext_cmd;
ext_cmd = findcom(tp->name, FC_FUNC | FC_PATH);
if (ext_cmd && (ext_cmd->type == CFUNC ||
(ext_cmd->flag & ISSET)))
tp = ext_cmd;
}
break;
} else if (tp->val.f == c_trap) {
t->u.evalflags &= ~DOTCOMEXEC;
break;
} else
break;
tp = findcom(ap[0], fcflags & (FC_BI | FC_FUNC));
}
if (t->u.evalflags & DOTCOMEXEC)
flags |= XEXEC;
l_expand = e->loc;
if (!resetspec && (!ap[0] || (tp && (tp->flag & KEEPASN))))
type_flags = 0;
else {
/* create new variable/function block */
newblock();
/* all functions keep assignments */
type_flags = LOCAL | LOCAL_COPY | EXPORT;
}
l_assign = e->loc;
if (exec_clrenv)
l_assign->flags |= BF_STOPENV;
if (Flag(FEXPORT))
type_flags |= EXPORT;
if (Flag(FXTRACE))
change_xtrace(2, Nee);
for (i = 0; t->vars[i]; i++) {
/* do NOT lookup in the new var/fn block just created */
e->loc = l_expand;
cp = evalstr(t->vars[i], DOASNTILDE | DOSCALAR);
e->loc = l_assign;
if (Flag(FXTRACE)) {
const char *ccp;
ccp = skip_varname(cp, Ja);
if (*ccp == '+')
++ccp;
if (*ccp == '=')
++ccp;
shf_write(cp, ccp - cp, shl_xtrace);
print_value_quoted(shl_xtrace, ccp);
shf_putc(' ', shl_xtrace);
}
/* but assign in there as usual */
typeset(cp, type_flags, 0, 0, 0);
}
if (Flag(FXTRACE)) {
change_xtrace(2, Nee);
if (ap[rv = 0]) {
xtrace_ap_loop:
print_value_quoted(shl_xtrace, ap[rv]);
if (ap[++rv]) {
shf_putc(' ', shl_xtrace);
goto xtrace_ap_loop;
}
}
change_xtrace(1, Nee);
}
if ((cp = *ap) == NULL) {
rv = subst_exstat;
goto Leave;
} else if (!tp) {
if (Flag(FRESTRICTED) && mksh_vdirsep(cp)) {
kwarnf(KWF_PREFIX | KWF_FILELINE | KWF_TWOMSG |
KWF_NOERRNO, cp, "restricted");
rv = 1;
goto Leave;
}
tp = findcom(cp, fcflags);
}
switch (tp->type) {
/* shell built-in */
case CSHELL:
do_call_builtin:
if (l_expand != l_assign)
l_assign->flags |= (tp->flag & NEXTLOC_BI);
rv = call_builtin(tp, (const char **)ap, null, resetspec);
break;
/* function call */
case CFUNC:
if (!(tp->flag & ISSET)) {
struct tbl *ftp;
if (!tp->u.fpath) {
fpath_error:
rv = (tp->u2.errnov == ENOENT) ? 127 : 126;
kwarnf(KWF_ERR(rv) | KWF_VERRNO |
KWF_PREFIX | KWF_FILELINE | KWF_TWOMSG,
tp->u2.errnov, cp,
"function definition file");
break;
}
errno = 0;
if (include(tp->u.fpath, NULL, Nee) < 0 ||
!(ftp = findfunc(cp, hash(cp), Nee)) ||
!(ftp->flag & ISSET)) {
rv = errno;
if ((ftp = findcom(cp, FC_BI)) &&
(ftp->type == CSHELL) &&
(ftp->flag & LOW_BI)) {
tp = ftp;
goto do_call_builtin;
}
if (rv) {
tp->u2.errnov = rv;
cp = tp->u.fpath;
goto fpath_error;
}
kwarnf0(KWF_ERR(127) |
KWF_PREFIX | KWF_FILELINE | KWF_NOERRNO,
Tf_sD_s_s, cp,
"function not defined by", tp->u.fpath);
rv = 127;
break;
}
tp = ftp;
}
/*
* ksh functions set $0 to function name, POSIX
* functions leave $0 unchanged.
*/
old_kshname = kshname;
if (tp->flag & FKSH)
kshname = ap[0];
else
ap[0] = kshname;
e->loc->argv = ap;
for (i = 0; *ap++ != NULL; i++)
;
e->loc->argc = i - 1;
/*
* ksh-style functions handle getopts sanely,
* Bourne/POSIX functions are insane...
*/
if (tp->flag & FKSH) {
e->loc->flags |= BF_DOGETOPTS;
e->loc->getopts_state = user_opt;
getopts_reset(1);
}
for (type_flags = 0; type_flags < FNFLAGS; ++type_flags)
old_flags[type_flags] = shell_flags[type_flags];
change_xtrace((Flag(FXTRACEREC) ? Flag(FXTRACE) : 0) |
((tp->flag & TRACE) ? 1 : 0), Nee);
old_inuse = tp->flag & FINUSE;
tp->flag |= FINUSE;
e->type = E_FUNC;
if (!(i = kshsetjmp(e->jbuf))) {
execute(tp->val.t, flags & XERROK, NULL);
i = LRETURN;
}
kshname = old_kshname;
change_xtrace(old_flags[(int)FXTRACE], Nee);
#ifndef MKSH_LEGACY_MODE
if (tp->flag & FKSH) {
/* Korn style functions restore Flags on return */
old_flags[(int)FXTRACE] = Flag(FXTRACE);
/* some must not be restored / need special handling */
for (type_flags = 0; type_flags < FNFLAGS; ++type_flags)
#ifndef MKSH_UNEMPLOYED
if (type_flags == FMONITOR)
change_flag(type_flags, OF_INTERNAL,
old_flags[type_flags]);
else
#endif
if (type_flags != FPRIVILEGED)
shell_flags[type_flags] =
old_flags[type_flags];
}
#endif
tp->flag = (tp->flag & ~FINUSE) | old_inuse;
/*
* Were we deleted while executing? If so, free the
* execution tree.
*/
if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
if (tp->flag & ALLOC) {
tp->flag &= ~ALLOC;
tfree(tp->val.t, tp->areap);
}
tp->flag = 0;
}
switch (i) {
case LRETURN:
case LERROR:
case LERREXT:
rv = exstat & 0xFF;
break;
case LRDERR:
case LINTR:
case LEXIT:
case LLEAVE:
case LSHELL:
quitenv(NULL);
unwind(i);
/* NOTREACHED */
default:
quitenv(NULL);
kerrf0(KWF_INTERNAL | KWF_ERR(0xFF) | KWF_NOERRNO,
Tunexpected_type, Tunwind, Tfunction, i);
}
break;
/* executable command */
case CEXEC:
/* tracked alias */
case CTALIAS:
if (!(tp->flag&ISSET)) {
if (tp->u2.errnov == ENOENT) {
rv = 127;
kwarnf(KWF_ERR(127) |
KWF_PREFIX | KWF_FILELINE | KWF_TWOMSG |
KWF_NOERRNO, cp, Tinacc_not_found);
} else {
rv = 126;
kwarnf(KWF_ERR(126) | KWF_VERRNO |
KWF_PREFIX | KWF_FILELINE | KWF_TWOMSG,
tp->u2.errnov, cp, "can't execute");
}
break;
}
/* set $_ to program's full path */
/* setstr() can't fail here */
setstr(typeset("_", LOCAL | EXPORT, 0, INTEGER, 0),
tp->val.s, KSH_RETURN_ERROR);
/* to fork, we set up a TEXEC node and call execute */
texec.type = TEXEC;
/* for vistree/dumptree */
texec.left = t;
texec.str = tp->val.s;
texec.args = ap;
/* in this case we do not fork, of course */
if (flags & XEXEC) {
if (exec_argv0)
texec.args[0] = exec_argv0;
j_exit();
}
rv = exchild(&texec, flags, xerrok, -1);
break;
}
Leave:
if (flags & XEXEC) {
exstat = rv & 0xFF;
unwind(LEXIT);
}
return (rv);
}
static void
scriptexec(struct op *tp, const char **ap)
{
const char *sh;
#ifndef MKSH_SMALL
int fd;
unsigned char buf[68];
#endif
union mksh_ccphack args, cap;
sh = str_val(global(TEXECSHELL));
if (sh && *sh)
sh = search_path(sh, path, X_OK, NULL);
if (!sh || !*sh)
sh = MKSH_DEFAULT_EXECSHELL;
*tp->args-- = tp->str;
#ifndef MKSH_SMALL
if ((fd = binopen2(tp->str, O_RDONLY | O_MAYEXEC)) >= 0) {
unsigned char *cp;
unsigned short m;
ssize_t n;
#ifdef __OS2__
const char *str;
#endif
/* read first couple of octets from file */
n = read(fd, buf, sizeof(buf) - 1);
close(fd);
/* read error or short read? */
if (n < 5)
goto nomagic;
/* terminate buffer */
buf[n] = '\0';
/* scan for shebang magic */
if (ord(buf[0]) == ORD('#') && ord(buf[1]) == ORD('!'))
n = 2;
#ifdef __OS2__
else if (n > 8 && !strncmp((char *)buf, Textproc, 7) &&
ctype(buf[7], C_BLANK))
n = 8;
#endif
else
goto noshebang;
/* scan for newline or NUL (end of buffer) */
cp = buf + n;
while (!ctype(*cp, C_NL | C_NUL))
++cp;
/* if the shebang line is longer than MAXINTERP, bail out */
if (!*cp)
kerrf0(KWF_ERR(126) | KWF_PREFIX | KWF_FILELINE |
KWF_NOERRNO, "%s: not executable: shebang too long",
tp->str);
/* replace newline by NUL */
*cp = '\0';
/* restore start of shebang position */
cp = buf + n;
/* skip whitespace before shell name */
while (ctype(*cp, C_BLANK))
++cp;
/* just whitespace on the line? */
if (*cp == '\0')
goto noshebang;
/* no, we actually found an interpreter name */
sh = (char *)cp;
/* look for end of shell/interpreter name */
while (!ctype(*cp, C_BLANK | C_NUL))
++cp;
/* any arguments? */
if (*cp) {
*cp++ = '\0';
/* skip spaces before arguments */
while (ctype(*cp, C_BLANK))
++cp;
/* pass it all in ONE argument (historic reasons) */
if (*cp)
*tp->args-- = (char *)cp;
}
#ifdef __OS2__
/*
* On OS/2, the directory structure differs from normal
* Unix, which can make many scripts whose shebang
* hardcodes the path to an interpreter fail (and there
* might be no /usr/bin/env); for user convenience, if
* the specified interpreter is not usable, do a PATH
* search to find it.
*/
if (mksh_vdirsep(sh) && !search_path(sh, path, X_OK, NULL)) {
str = search_path(_getname(sh), path, X_OK, NULL);
if (str)
sh = str;
}
#endif
goto nomagic;
noshebang:
m = ord(rtt2asc(buf[0])) << 8 | ord(rtt2asc(buf[1]));
if (m == 0x7F45 && ord(buf[2]) == ORD('L') &&
ord(buf[3]) == ORD('F'))
kerrf0(KWF_ERR(126) | KWF_PREFIX | KWF_FILELINE |
KWF_NOERRNO, "%s: not executable: %u-bit ELF file",
tp->str, 32U * buf[4]);