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mksh/exec.c

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/* $OpenBSD: exec.c,v 1.49 2009/01/29 23:27:26 jaredy Exp $ */
/*-
* Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
* Thorsten Glaser <tg@mirbsd.org>
*
* 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 1.84 2011/01/09 21:57:25 tg Exp $");
#ifndef MKSH_DEFAULT_EXECSHELL
#define MKSH_DEFAULT_EXECSHELL "/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 **);
static int iosetup(struct ioword *, struct tbl *);
static int herein(const char *, int, char **);
static const char *do_selectargs(const char **, bool);
static Test_op dbteste_isa(Test_env *, Test_meta);
static const char *dbteste_getopnd(Test_env *, Test_op, bool);
static void dbteste_error(Test_env *, int, const char *);
/*
* execute command tree
*/
int
execute(struct op * volatile t,
volatile int flags, /* if XEXEC don't fork */
volatile int * volatile xerrok)
{
int i;
volatile int rv = 0, dummy = 0;
int pv[2];
const char ** volatile ap;
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);
if (t->type == TCOM /* we want to run an executable... */) {
/* 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]->heredoc, t->ioact[0]->flag & IOEVAL,
&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(T_oomem, (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;
current_lineno = t->lineno; /* for $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));
}
/* 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);
ksh_dup2(pv[1], 1, false); /* stdout of curr */
/**
* 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]);
ksh_dup2(pv[0], 0, false); /* stdin of next */
closepipe(pv);
flags |= XPIPEI;
t = t->right;
}
restfd(1, e->savefd[1]); /* stdout of last */
e->savefd[1] = 0; /* no need to re-restore this */
/* Let exchild() close 0 in parent, after fork, before wait */
i = exchild(t, flags | XPCLOSE, 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: {
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;
i = sigsetjmp(e->jbuf, 0);
if (i) {
sigprocmask(SIG_SETMASK, &omask, NULL);
quitenv(NULL);
unwind(i);
/* NOTREACHED */
}
/* 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);
coproc.readw = pv[1]; /* closed before first read */
coproc.njobs = 0;
/* create new coprocess id */
++coproc.id;
}
sigprocmask(SIG_SETMASK, &omask, NULL);
e->type = E_EXEC; /* no more need for error handler */
/* 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 (1) {
i = sigsetjmp(e->jbuf, 0);
if (!i)
break;
if ((e->flags&EF_BRKCONT_PASS) ||
(i != LBREAK && i != LCONTIN)) {
quitenv(NULL);
unwind(i);
} else if (i == LBREAK) {
rv = 0;
goto Break;
}
}
rv = 0; /* in case of a continue */
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 (1) {
i = sigsetjmp(e->jbuf, 0);
if (!i)
break;
if ((e->flags&EF_BRKCONT_PASS) ||
(i != LBREAK && i != LCONTIN)) {
quitenv(NULL);
unwind(i);
} else if (i == LBREAK) {
rv = 0;
goto Break;
}
}
rv = 0; /* in case of a continue */
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)
break; /* should be error */
rv = execute(t->left, XERROK, NULL) == 0 ?
execute(t->right->left, flags & XERROK, xerrok) :
execute(t->right->right, flags & XERROK, xerrok);
break;
case TCASE:
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 ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
gmatchx(ccp, s, false))
goto Found;
break;
Found:
rv = execute(t->left, flags & XERROK, xerrok);
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, strerror(rv));
}
Break:
exstat = rv;
quitenv(NULL); /* restores IO */
if ((flags&XEXEC))
unwind(LEXIT); /* exit child */
if (rv != 0 && !(flags & XERROK) &&
(xerrok == NULL || !*xerrok)) {
trapsig(SIGERR_);
if (Flag(FERREXIT))
unwind(LERROR);
}
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;
static struct op texec; /* Must be static (XXX but why?) */
int type_flags;
int keepasn_ok;
int fcflags = FC_BI|FC_FUNC|FC_PATH;
bool bourne_function_call = false;
struct block *l_expand, *l_assign;
/* snag the last argument for $_ 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()?.
*/
if (Flag(FTALKING) && *(lastp = ap)) {
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
*/
keepasn_ok = 1;
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)
errorf("%s: %s: %s", T_builtin, cp, "not a builtin");
continue;
} else if (tp->val.f == c_exec) {
if (ap[1] == NULL)
break;
ap++;
flags |= XEXEC;
} else if (tp->val.f == c_command) {
int optc, saw_p = 0;
/* 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 = 1;
if (optc != EOF)
break; /* command -vV or something */
/* don't look for functions */
fcflags = FC_BI|FC_PATH;
if (saw_p) {
if (Flag(FRESTRICTED)) {
warningf(true, "%s: %s",
"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.
*/
keepasn_ok = 0;
if (!ap[0]) {
/* ensure command with no args exits with 0 */
subst_exstat = 0;
break;
}
} else if (tp->val.f == c_cat) {
/*
* if we have any flags, do not use the builtin
* in theory, we could allow -u, but that would
* mean to use ksh_getopt here and possibly ad-
* ded complexity and more code and isn't worth
*/
if (ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
/* argument, begins with -, is not - or -- */
(ap[1][1] != '-' || ap[1][2] != '\0'))
/* don't look for builtins or functions */
fcflags = FC_PATH;
else
/* go on, use the builtin */
break;
} else
break;
tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
}
l_expand = e->loc;
if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
type_flags = 0;
else {
/* create new variable/function block */
newblock();
/* ksh functions don't keep assignments, POSIX functions do. */
if (keepasn_ok && tp && tp->type == CFUNC &&
!(tp->flag & FKSH)) {
bourne_function_call = true;
type_flags = EXPORT;
} else
type_flags = LOCAL|LOCAL_COPY|EXPORT;
}
l_assign = e->loc;
if (Flag(FEXPORT))
type_flags |= EXPORT;
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);
e->loc = l_assign;
/* but assign in there as usual */
if (Flag(FXTRACE)) {
if (i == 0)
shf_puts(substitute(str_val(global("PS4")), 0),
shl_out);
shf_fprintf(shl_out, "%s%c", cp,
t->vars[i + 1] ? ' ' : '\n');
if (!t->vars[i + 1])
shf_flush(shl_out);
}
typeset(cp, type_flags, 0, 0, 0);
if (bourne_function_call && !(type_flags & EXPORT))
typeset(cp, LOCAL|LOCAL_COPY|EXPORT, 0, 0, 0);
}
if ((cp = *ap) == NULL) {
rv = subst_exstat;
goto Leave;
} else if (!tp) {
if (Flag(FRESTRICTED) && vstrchr(cp, '/')) {
warningf(true, "%s: %s", cp, "restricted");
rv = 1;
goto Leave;
}
tp = findcom(cp, fcflags);
}
switch (tp->type) {
case CSHELL: /* shell built-in */
rv = call_builtin(tp, (const char **)ap);
break;
case CFUNC: { /* function call */
volatile unsigned char old_xflag;
volatile Tflag old_inuse;
const char * volatile old_kshname;
if (!(tp->flag & ISSET)) {
struct tbl *ftp;
if (!tp->u.fpath) {
if (tp->u2.errno_) {
warningf(true, "%s: %s %s: %s", cp,
"can't find",
"function definition file",
strerror(tp->u2.errno_));
rv = 126;
} else {
warningf(true, "%s: %s %s", cp,
"can't find",
"function definition file");
rv = 127;
}
break;
}
if (include(tp->u.fpath, 0, NULL, 0) < 0) {
rv = errno;
warningf(true, "%s: %s %s %s: %s", cp,
"can't open", "function definition file",
tp->u.fpath, strerror(rv));
rv = 127;
break;
}
if (!(ftp = findfunc(cp, hash(cp), false)) ||
!(ftp->flag & ISSET)) {
warningf(true, "%s: %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);
}
old_xflag = Flag(FXTRACE);
Flag(FXTRACE) = tp->flag & TRACE ? 1 : 0;
old_inuse = tp->flag & FINUSE;
tp->flag |= FINUSE;
e->type = E_FUNC;
i = sigsetjmp(e->jbuf, 0);
if (i == 0) {
/* seems odd to pass XERROK here, but AT&T ksh does */
exstat = execute(tp->val.t, flags & XERROK, xerrok);
i = LRETURN;
}
kshname = old_kshname;
Flag(FXTRACE) = old_xflag;
tp->flag = (tp->flag & ~FINUSE) | old_inuse;
/* Were we deleted while executing? If so, free the execution
* tree. todo: Unfortunately, the table entry is never re-used
* until the lookup table is expanded.
*/
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:
rv = exstat;
break;
case LINTR:
case LEXIT:
case LLEAVE:
case LSHELL:
quitenv(NULL);
unwind(i);
/* NOTREACHED */
default:
quitenv(NULL);
internal_errorf("%s %d", "CFUNC", i);
}
break;
}
case CEXEC: /* executable command */
case CTALIAS: /* tracked alias */
if (!(tp->flag&ISSET)) {
/* errno_ will be set if the named command was found
* but could not be executed (permissions, no execute
* bit, directory, etc). Print out a (hopefully)
* useful error message and set the exit status to 126.
*/
if (tp->u2.errno_) {
warningf(true, "%s: %s: %s", cp,
"can't execute", strerror(tp->u2.errno_));
rv = 126; /* POSIX */
} else {
warningf(true, "%s: %s", cp, "not found");
rv = 127;
}
break;
}
/* set $_ to programme's full path */
/* setstr() can't fail here */
setstr(typeset("_", LOCAL|EXPORT, 0, INTEGER, 0),
tp->val.s, KSH_RETURN_ERROR);
if (flags&XEXEC) {
j_exit();
if (!(flags&XBGND)
#ifndef MKSH_UNEMPLOYED
|| Flag(FMONITOR)
#endif
) {
setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
}
}
/* to fork we set up a TEXEC node and call execute */
texec.type = TEXEC;
texec.left = t; /* for tprint */
texec.str = tp->val.s;
texec.args = ap;
rv = exchild(&texec, flags, xerrok, -1);
break;
}
Leave:
if (flags & XEXEC) {
exstat = rv;
unwind(LLEAVE);
}
return (rv);
}
static void
scriptexec(struct op *tp, const char **ap)
{
const char *sh;
#ifndef MKSH_SMALL
unsigned char *cp;
char buf[64]; /* 64 == MAXINTERP in MirBSD <sys/param.h> */
int fd;
#endif
union mksh_ccphack args, cap;
sh = str_val(global("EXECSHELL"));
if (sh && *sh)
sh = search(sh, path, X_OK, NULL);
if (!sh || !*sh)
sh = MKSH_DEFAULT_EXECSHELL;
*tp->args-- = tp->str;
#ifndef MKSH_SMALL
if ((fd = open(tp->str, O_RDONLY)) >= 0) {
/* read first MAXINTERP octets from file */
if (read(fd, buf, sizeof(buf)) <= 0)
/* read error -> no good */
buf[0] = '\0';
close(fd);
/* scan for newline (or CR) or NUL _before_ end of buffer */
cp = (unsigned char *)buf;
while ((char *)cp < (buf + sizeof(buf)))
if (*cp == '\0' || *cp == '\n' || *cp == '\r') {
*cp = '\0';
break;
} else
++cp;
/* if the shebang line is longer than MAXINTERP, bail out */
if ((char *)cp >= (buf + sizeof(buf)))
goto noshebang;
/* skip UTF-8 Byte Order Mark, if present */
cp = (unsigned char *)buf;
if ((cp[0] == 0xEF) && (cp[1] == 0xBB) && (cp[2] == 0xBF))
cp += 3;
/* bail out if read error (above) or no shebang */
if ((cp[0] != '#') || (cp[1] != '!'))
goto noshebang;
cp += 2;
/* skip whitespace before shell name */
while (*cp == ' ' || *cp == '\t')
++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 (*cp != ' ' && *cp != '\t' && *cp != '\0')
++cp;
/* any arguments? */
if (*cp) {
*cp++ = '\0';
/* skip spaces before arguments */
while (*cp == ' ' || *cp == '\t')
++cp;
/* pass it all in ONE argument (historic reasons) */
if (*cp)
*tp->args-- = (char *)cp;
}
noshebang:
fd = buf[0] << 8 | buf[1];
if ((fd == /* OMAGIC */ 0407) ||
(fd == /* NMAGIC */ 0410) ||
(fd == /* ZMAGIC */ 0413) ||
(fd == /* QMAGIC */ 0314) ||
(fd == /* ECOFF_I386 */ 0x4C01) ||
(fd == /* ECOFF_M68K */ 0x0150 || fd == 0x5001) ||
(fd == /* ECOFF_SH */ 0x0500 || fd == 0x0005) ||
(fd == 0x7F45 && buf[2] == 'L' && buf[3] == 'F') ||
(fd == /* "MZ" */ 0x4D5A) ||
(fd == /* gzip */ 0x1F8B))
errorf("%s: not executable: magic %04X", tp->str, fd);
}
#endif
args.ro = tp->args;
*args.ro = sh;
cap.ro = ap;
execve(args.rw[0], args.rw, cap.rw);
/* report both the programme that was run and the bogus interpreter */
errorf("%s: %s: %s", tp->str, sh, strerror(errno));
}
int
shcomexec(const char **wp)
{
struct tbl *tp;
tp = ktsearch(&builtins, *wp, hash(*wp));
if (tp == NULL)
internal_errorf("%s: %s", "shcomexec", *wp);
return (call_builtin(tp, wp));
}
/*
* Search function tables for a function. If create set, a table entry
* is created if none is found.
*/
struct tbl *
findfunc(const char *name, uint32_t h, bool create)
{
struct block *l;
struct tbl *tp = NULL;
for (l = e->loc; l; l = l->next) {
tp = ktsearch(&l->funs, name, h);
if (tp)
break;
if (!l->next && create) {
tp = ktenter(&l->funs, name, h);
tp->flag = DEFINED;
tp->type = CFUNC;
tp->val.t = NULL;
break;
}
}
return (tp);
}
/*
* define function. Returns 1 if function is being undefined (t == 0) and
* function did not exist, returns 0 otherwise.
*/
int
define(const char *name, struct op *t)
{
struct tbl *tp;
bool was_set = false;
while (1) {
tp = findfunc(name, hash(name), true);
if (tp->flag & ISSET)
was_set = true;
/* If this function is currently being executed, we zap this
* table entry so findfunc() won't see it
*/
if (tp->flag & FINUSE) {
tp->name[0] = '\0';
tp->flag &= ~DEFINED; /* ensure it won't be found */
tp->flag |= FDELETE;
} else
break;
}
if (tp->flag & ALLOC) {
tp->flag &= ~(ISSET|ALLOC);
tfree(tp->val.t, tp->areap);
}
if (t == NULL) { /* undefine */
ktdelete(tp);
return (was_set ? 0 : 1);
}
tp->val.t = tcopy(t->left, tp->areap);
tp->flag |= (ISSET|ALLOC);
if (t->u.ksh_func)
tp->flag |= FKSH;
return (0);
}
/*
* add builtin
*/
void
builtin(const char *name, int (*func) (const char **))
{
struct tbl *tp;
Tflag flag;
/* see if any flags should be set for this builtin */
for (flag = 0; ; name++) {
if (*name == '=') /* command does variable assignment */
flag |= KEEPASN;
else if (*name == '*') /* POSIX special builtin */
flag |= SPEC_BI;
else if (*name == '+') /* POSIX regular builtin */
flag |= REG_BI;
else
break;
}
tp = ktenter(&builtins, name, hash(name));
tp->flag = DEFINED | flag;
tp->type = CSHELL;
tp->val.f = func;
}
/*
* find command
* either function, hashed command, or built-in (in that order)
*/
struct tbl *
findcom(const char *name, int flags)
{
static struct tbl temp;
uint32_t h = hash(name);
struct tbl *tp = NULL, *tbi;
unsigned char insert = Flag(FTRACKALL); /* insert if not found */
char *fpath; /* for function autoloading */
union mksh_cchack npath;
if (vstrchr(name, '/')) {
insert = 0;
/* prevent FPATH search below */
flags &= ~FC_FUNC;
goto Search;
}
tbi = (flags & FC_BI) ? ktsearch(&builtins, name, h) : NULL;
/* POSIX says special builtins first, then functions, then
* POSIX regular builtins, then search path...
*/
if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
tp = tbi;
if (!tp && (flags & FC_FUNC)) {
tp = findfunc(name, h, false);
if (tp && !(tp->flag & ISSET)) {
if ((fpath = str_val(global("FPATH"))) == null) {
tp->u.fpath = NULL;
tp->u2.errno_ = 0;
} else
tp->u.fpath = search(name, fpath, R_OK,
&tp->u2.errno_);
}
}
if (!tp && (flags & FC_REGBI) && tbi && (tbi->flag & REG_BI))
tp = tbi;
if (!tp && (flags & FC_UNREGBI) && tbi)
tp = tbi;
if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
tp = ktsearch(&taliases, name, h);
if (tp && (tp->flag & ISSET) && access(tp->val.s, X_OK) != 0) {
if (tp->flag & ALLOC) {
tp->flag &= ~ALLOC;
afree(tp->val.s, APERM);
}
tp->flag &= ~ISSET;
}
}
Search:
if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET))) &&
(flags & FC_PATH)) {
if (!tp) {
if (insert && !(flags & FC_DEFPATH)) {
tp = ktenter(&taliases, name, h);
tp->type = CTALIAS;
} else {
tp = &temp;
tp->type = CEXEC;
}
tp->flag = DEFINED; /* make ~ISSET */
}
npath.ro = search(name, flags & FC_DEFPATH ? def_path : path,
X_OK, &tp->u2.errno_);
if (npath.ro) {
strdupx(tp->val.s, npath.ro, APERM);
if (npath.ro != name)
afree(npath.rw, ATEMP);
tp->flag |= ISSET|ALLOC;
} else if ((flags & FC_FUNC) &&
(fpath = str_val(global("FPATH"))) != null &&
(npath.ro = search(name, fpath, R_OK,
&tp->u2.errno_)) != NULL) {
/* An undocumented feature of AT&T ksh is that it
* searches FPATH if a command is not found, even
* if the command hasn't been set up as an autoloaded
* function (ie, no typeset -uf).
*/
tp = &temp;
tp->type = CFUNC;
tp->flag = DEFINED; /* make ~ISSET */
tp->u.fpath = npath.ro;
}
}
return (tp);
}
/*
* flush executable commands with relative paths
*/
void
flushcom(int all) /* just relative or all */
{
struct tbl *tp;
struct tstate ts;
for (ktwalk(&ts, &taliases); (tp = ktnext(&ts)) != NULL; )
if ((tp->flag&ISSET) && (all || tp->val.s[0] != '/')) {
if (tp->flag&ALLOC) {
tp->flag &= ~(ALLOC|ISSET);
afree(tp->val.s, APERM);
}
tp->flag &= ~ISSET;
}
}
/* Check if path is something we want to find. Returns -1 for failure. */
int
search_access(const char *lpath, int mode,
int *errnop) /* set if candidate found, but not suitable */
{
int ret, err = 0;
struct stat statb;
if (stat(lpath, &statb) < 0)
return (-1);
ret = access(lpath, mode);
if (ret < 0)
err = errno; /* File exists, but we can't access it */
else if (mode == X_OK && (!S_ISREG(statb.st_mode) ||
!(statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)))) {
/* This 'cause access() says root can execute everything */
ret = -1;
err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
}
if (err && errnop && !*errnop)
*errnop = err;
return (ret);
}
/*
* search for command with PATH
*/
const char *
search(const char *name, const char *lpath,
int mode, /* R_OK or X_OK */
int *errnop) /* set if candidate found, but not suitable */
{
const char *sp, *p;
char *xp;
XString xs;
int namelen;
if (errnop)
*errnop = 0;
if (vstrchr(name, '/')) {
if (search_access(name, mode, errnop) == 0)
return (name);
return (NULL);
}
namelen = strlen(name) + 1;
Xinit(xs, xp, 128, ATEMP);
sp = lpath;
while (sp != NULL) {
xp = Xstring(xs, xp);
if (!(p = cstrchr(sp, ':')))
p = sp + strlen(sp);
if (p != sp) {
XcheckN(xs, xp, p - sp);
memcpy(xp, sp, p - sp);
xp += p - sp;
*xp++ = '/';
}
sp = p;
XcheckN(xs, xp, namelen);
memcpy(xp, name, namelen);
if (search_access(Xstring(xs, xp), mode, errnop) == 0)
return (Xclose(xs, xp + namelen));
if (*sp++ == '\0')
sp = NULL;
}
Xfree(xs, xp);
return (NULL);
}
static int
call_builtin(struct tbl *tp, const char **wp)
{
int rv;
builtin_argv0 = wp[0];
builtin_flag = tp->flag;
shf_reopen(1, SHF_WR, shl_stdout);
shl_stdout_ok = true;
ksh_getopt_reset(&builtin_opt, GF_ERROR);
rv = (*tp->val.f)(wp);
shf_flush(shl_stdout);
shl_stdout_ok = false;
builtin_flag = 0;
builtin_argv0 = NULL;
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;
int do_open = 1, do_close = 0, 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 = 0;
/* herein() returns -2 if error has been printed */
u = herein(iop->heredoc, iop->flag & IOEVAL, NULL);
/* cp may have wrong name */
break;
case IODUP: {
const char *emsg;
do_open = 0;
if (*cp == '-' && !cp[1]) {
u = 1009; /* prevent error return below */
do_close = 1;
} 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)
return (0); /* "dup from" == "dup to" */
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, strerror(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 ev;
ev = errno;
warningf(true, "%s %s %s",
"can't finish (dup) redirection",
snptreef(NULL, 32, "%R", &iotmp),
strerror(ev));
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);
}
/*
* Process here documents by providing the content, either as
* result (globally allocated) string or in a temp file; if
* unquoted, the string is expanded first.
*/
static int
hereinval(const char *content, int sub, char **resbuf, struct shf *shf)
{
const char *ccp;
struct source *s, *osource;
osource = source;
newenv(E_ERRH);
if (sigsetjmp(e->jbuf, 0)) {
source = osource;
quitenv(shf);
/* special to iosetup(): don't print error */
return (-2);
}
if (sub) {
/* do substitutions on the content of heredoc */
s = pushs(SSTRING, ATEMP);
s->start = s->str = content;
source = s;
if (yylex(ONEWORD|HEREDOC) != LWORD)
internal_errorf("%s: %s", "herein", "yylex");
source = osource;
ccp = evalstr(yylval.cp, 0);
} else
ccp = content;
if (resbuf == NULL)
shf_puts(ccp, shf);
else
strdupx(*resbuf, ccp, APERM);
quitenv(NULL);
return (0);
}
static int
herein(const char *content, int sub, char **resbuf)
{
int fd = -1;
struct shf *shf;
struct temp *h;
int i;
/* ksh -c 'cat << EOF' can cause this... */
if (content == NULL) {
warningf(true, "%s missing", "here document");
/* special to iosetup(): don't print error */
return (-2);
}
/* skip all the fd setup if we just want the value */
if (resbuf != NULL)
return (hereinval(content, sub, resbuf, NULL));
/*
* Create temp file to hold content (done before newenv
* so temp doesn't get removed too soon).
*/
h = maketemp(ATEMP, TT_HEREDOC_EXP, &e->temps);
if (!(shf = h->shf) || (fd = open(h->name, O_RDONLY, 0)) < 0) {
i = errno;
warningf(true, "can't %s temporary file %s: %s",
!shf ? "create" : "open", h->name, strerror(i));
if (shf)
shf_close(shf);
/* special to iosetup(): don't print error */
return (-2);
}
if (hereinval(content, sub, NULL, shf) == -2) {
close(fd);
/* special to iosetup(): don't print error */
return (-2);
}
if (shf_close(shf) == EOF) {
i = errno;
close(fd);
warningf(true, "%s: %s: %s", "write", h->name, strerror(i));
/* special to iosetup(): don't print error */
return (-2);
}
return (fd);
}
/*
* ksh special - the select command processing section
* print the args in column form - assuming that we can
*/
static const char *
do_selectargs(const char **ap, bool print_menu)
{
static const char *read_args[] = {
"read", "-r", "REPLY", NULL
};
char *s;
int i, argct;
for (argct = 0; ap[argct]; argct++)
;
while (1) {
/* Menu is printed if
* - this is the first time around the select loop
* - the user enters a blank line
* - the REPLY parameter is empty
*/
if (print_menu || !*str_val(global("REPLY")))
pr_menu(ap);
shellf("%s", str_val(global("PS3")));
if (call_builtin(findcom("read", FC_BI), read_args))
return (NULL);
s = str_val(global("REPLY"));
if (*s) {
getn(s, &i);
return ((i >= 1 && i <= argct) ? ap[i - 1] : null);
}
print_menu = 1;
}
}
struct select_menu_info {
const char * const *args;
int num_width;
};
static char *select_fmt_entry(char *, int, int, const void *);
/* format a single select menu item */
static char *
select_fmt_entry(char *buf, int buflen, int i, const void *arg)
{
const struct select_menu_info *smi =
(const struct select_menu_info *)arg;
shf_snprintf(buf, buflen, "%*d) %s",
smi->num_width, i + 1, smi->args[i]);
return (buf);
}
/*
* print a select style menu
*/
int
pr_menu(const char * const *ap)
{
struct select_menu_info smi;
const char * const *pp;
int acols = 0, aocts = 0, i, n;
/*
* width/column calculations were done once and saved, but this
* means select can't be used recursively so we re-calculate
* each time (could save in a structure that is returned, but
* it's probably not worth the bother)
*/
/*
* get dimensions of the list
*/
for (n = 0, pp = ap; *pp; n++, pp++) {
i = strlen(*pp);
if (i > aocts)
aocts = i;
i = utf_mbswidth(*pp);
if (i > acols)
acols = i;
}
/*
* we will print an index of the form "%d) " in front of
* each entry, so get the maximum width of this
*/
for (i = n, smi.num_width = 1; i >= 10; i /= 10)
smi.num_width++;
smi.args = ap;
print_columns(shl_out, n, select_fmt_entry, (void *)&smi,
smi.num_width + 2 + aocts, smi.num_width + 2 + acols,
true);
return (n);
}
/* XXX: horrible kludge to fit within the framework */
static char *plain_fmt_entry(char *, int, int, const void *);
static char *
plain_fmt_entry(char *buf, int buflen, int i, const void *arg)
{
strlcpy(buf, ((const char * const *)arg)[i], buflen);
return (buf);
}
int
pr_list(char * const *ap)
{
int acols = 0, aocts = 0, i, n;
char * const *pp;
for (n = 0, pp = ap; *pp; n++, pp++) {
i = strlen(*pp);
if (i > aocts)
aocts = i;
i = utf_mbswidth(*pp);
if (i > acols)
acols = i;
}
print_columns(shl_out, n, plain_fmt_entry, (const void *)ap,
aocts, acols, false);
return (n);
}
/*
* [[ ... ]] evaluation routines
*/
/*
* Test if the current token is a whatever. Accepts the current token if
* it is. Returns 0 if it is not, non-zero if it is (in the case of
* TM_UNOP and TM_BINOP, the returned value is a Test_op).
*/
static Test_op
dbteste_isa(Test_env *te, Test_meta meta)
{
Test_op ret = TO_NONOP;
int uqword;
const char *p;
if (!*te->pos.wp)
return (meta == TM_END ? TO_NONNULL : TO_NONOP);
/* unquoted word? */
for (p = *te->pos.wp; *p == CHAR; p += 2)
;
uqword = *p == EOS;
if (meta == TM_UNOP || meta == TM_BINOP) {
if (uqword) {
char buf[8]; /* longer than the longest operator */
char *q = buf;
for (p = *te->pos.wp;
*p == CHAR && q < &buf[sizeof(buf) - 1]; p += 2)
*q++ = p[1];
*q = '\0';
ret = test_isop(meta, buf);
}
} else if (meta == TM_END)
ret = TO_NONOP;
else
ret = (uqword && !strcmp(*te->pos.wp,
dbtest_tokens[(int)meta])) ? TO_NONNULL : TO_NONOP;
/* Accept the token? */
if (ret != TO_NONOP)
te->pos.wp++;
return (ret);
}
static const char *
dbteste_getopnd(Test_env *te, Test_op op, bool do_eval)
{
const char *s = *te->pos.wp;
if (!s)
return (NULL);
te->pos.wp++;
if (!do_eval)
return (null);
if (op == TO_STEQL || op == TO_STNEQ)
s = evalstr(s, DOTILDE | DOPAT);
else
s = evalstr(s, DOTILDE);
return (s);
}
static void
dbteste_error(Test_env *te, int offset, const char *msg)
{
te->flags |= TEF_ERROR;
internal_warningf("dbteste_error: %s (offset %d)", msg, offset);
}
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