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exec.c
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/* $OpenBSD: exec.c,v 1.74 2019/06/28 13:34:59 deraadt Exp $ */
/*
* execute command tree
*/
#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "sh.h"
#include "c_test.h"
/* Does ps4 get parameter substitutions done? */
# define PS4_SUBSTITUTE(s) substitute((s), 0)
static int comexec(struct op *, struct tbl *volatile, char **,
int volatile, volatile int *);
static void scriptexec(struct op *, char **);
static int call_builtin(struct tbl *, char **);
static int iosetup(struct ioword *, struct tbl *);
static int herein(const char *, int);
static char *do_selectargs(char **, bool);
static int dbteste_isa(Test_env *, Test_meta);
static const char *dbteste_getopnd(Test_env *, Test_op, int);
static int dbteste_eval(Test_env *, Test_op, const char *, const char *,
int);
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 *xerrok) /* inform recursive callers in -e mode that
* short-circuit && or || shouldn't be treated
* as an error */
{
int i, dummy = 0, save_xerrok = 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] ? " " : "\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) {
genv->savefd = areallocarray(NULL, NUFILE, sizeof(short), ATEMP);
/* initialize to not redirected */
memset(genv->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))
errorf(NULL);
/* Deal with FERREXIT, quitenv(), etc. */
goto Break;
}
}
switch (t->type) {
case TCOM:
rv = comexec(t, tp, ap, flags, xerrok);
break;
case TPAREN:
rv = execute(t->left, flags|XFORK, xerrok);
break;
case TPIPE:
flags |= XFORK;
flags &= ~XEXEC;
genv->savefd[0] = savefd(0);
genv->savefd[1] = savefd(1);
while (t->type == TPIPE) {
openpipe(pv);
(void) 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]);
(void) ksh_dup2(pv[0], 0, false); /* stdin of next */
closepipe(pv);
flags |= XPIPEI;
t = t->right;
}
restfd(1, genv->savefd[1]); /* stdout of last */
genv->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);
genv->type = E_ERRH;
i = sigsetjmp(genv->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 */
genv->savefd[0] = savefd(0);
genv->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);
genv->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 optimize
* 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;
*xerrok = 1;
}
break;
case TBANG:
rv = !execute(t->right, XERROK, xerrok);
flags |= 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 = dbteste_eval;
te.error = dbteste_error;
rv = test_parse(&te);
break;
}
case TFOR:
case TSELECT:
{
volatile bool is_first = true;
ap = (t->vars != NULL) ? eval(t->vars, DOBLANK|DOGLOB|DOTILDE) :
genv->loc->argv + 1;
genv->type = E_LOOP;
while (1) {
i = sigsetjmp(genv->jbuf, 0);
if (!i)
break;
if ((genv->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) {
save_xerrok = *xerrok;
while (*ap != NULL) {
setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
/* undo xerrok in all iterations except the
* last */
*xerrok = save_xerrok;
rv = execute(t->left, flags & XERROK, xerrok);
}
/* ripple xerrok set at final iteration */
} else { /* TSELECT */
for (;;) {
if (!(cp = do_selectargs(ap, is_first))) {
rv = 1;
break;
}
is_first = false;
setstr(global(t->str), cp, KSH_UNWIND_ERROR);
rv = execute(t->left, flags & XERROK, xerrok);
}
}
}
break;
case TWHILE:
case TUNTIL:
genv->type = E_LOOP;
while (1) {
i = sigsetjmp(genv->jbuf, 0);
if (!i)
break;
if ((genv->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:
cp = evalstr(t->str, DOTILDE);
for (t = t->left; t != NULL && t->type == TPAT; t = t->right) {
for (ap = t->vars; *ap; ap++) {
if ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
gmatch_(cp, 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];
ap = makenv();
restoresigs();
cleanup_proc_env();
execve(t->str, t->args, ap);
if (errno == ENOEXEC)
scriptexec(t, ap);
else
errorf("%s: %s", s, strerror(errno));
}
Break:
exstat = rv;
quitenv(NULL); /* restores IO */
if ((flags&XEXEC))
unwind(LEXIT); /* exit child */
if (rv != 0 && !(flags & XERROK) && !*xerrok) {
trapsig(SIGERR_);
if (Flag(FERREXIT))
unwind(LERROR);
}
return rv;
}
/*
* execute simple command
*/
static int
comexec(struct op *t, struct tbl *volatile tp, char **ap, volatile int flags,
volatile int *xerrok)
{
int i;
volatile int rv = 0;
char *cp;
char **lastp;
struct op texec;
int type_flags;
int keepasn_ok;
int fcflags = FC_BI|FC_FUNC|FC_PATH;
int bourne_function_call = 0;
/* 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(FSH) && 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) {
fcflags = FC_BI|FC_FUNC|FC_PATH;/* undo effects of command */
if (tp->val.f == c_builtin) {
if ((cp = *++ap) == NULL) {
tp = NULL;
break;
}
tp = findcom(cp, FC_BI);
if (tp == NULL)
errorf("builtin: %s: not a builtin", cp);
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,
"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
break;
tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
}
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 = 1;
type_flags = 0;
} else
type_flags = LOCAL|LOCAL_COPY|EXPORT;
}
if (Flag(FEXPORT))
type_flags |= EXPORT;
for (i = 0; t->vars[i]; i++) {
cp = evalstr(t->vars[i], DOASNTILDE);
if (Flag(FXTRACE)) {
if (i == 0)
shf_fprintf(shl_out, "%s",
PS4_SUBSTITUTE(str_val(global("PS4"))));
shf_fprintf(shl_out, "%s%s", 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) && strchr(cp, '/')) {
warningf(true, "%s: restricted", cp);
rv = 1;
goto Leave;
}
tp = findcom(cp, fcflags);
}
switch (tp->type) {
case CSHELL: /* shell built-in */
rv = call_builtin(tp, ap);
break;
case CFUNC: /* function call */
{
volatile int old_xflag, 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: can't find function "
"definition file - %s",
cp, strerror(tp->u2.errno_));
rv = 126;
} else {
warningf(true,
"%s: can't find function "
"definition file", cp);
rv = 127;
}
break;
}
if (include(tp->u.fpath, 0, NULL, 0) < 0) {
warningf(true,
"%s: can't open function definition file %s - %s",
cp, tp->u.fpath, strerror(errno));
rv = 127;
break;
}
if (!(ftp = findfunc(cp, hash(cp), false)) ||
!(ftp->flag & ISSET)) {
warningf(true,
"%s: function not defined by %s",
cp, 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] = (char *) kshname;
genv->loc->argv = ap;
for (i = 0; *ap++ != NULL; i++)
;
genv->loc->argc = i - 1;
/* ksh-style functions handle getopts sanely,
* bourne/posix functions are insane...
*/
if (tp->flag & FKSH) {
genv->loc->flags |= BF_DOGETOPTS;
genv->loc->getopts_state = user_opt;
getopts_reset(1);
}
old_xflag = Flag(FXTRACE);
Flag(FXTRACE) = tp->flag & TRACE ? true : false;
old_inuse = tp->flag & FINUSE;
tp->flag |= FINUSE;
genv->type = E_FUNC;
i = sigsetjmp(genv->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("CFUNC %d", 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: cannot execute - %s", cp,
strerror(tp->u2.errno_));
rv = 126; /* POSIX */
} else {
warningf(true, "%s: not found", cp);
rv = 127;
}
break;
}
if (!Flag(FSH)) {
/* set $_ to program'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) || Flag(FMONITOR)) {
setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
}
}
/* to fork we set up a TEXEC node and call execute */
memset(&texec, 0, sizeof(texec));
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, char **ap)
{
char *shell;
shell = str_val(global("EXECSHELL"));
if (shell && *shell)
shell = search(shell, search_path, X_OK, NULL);
if (!shell || !*shell)
shell = _PATH_BSHELL;
*tp->args-- = tp->str;
*tp->args = shell;
execve(tp->args[0], tp->args, ap);
/* report both the program that was run and the bogus shell */
errorf("%s: %s: %s", tp->str, shell, strerror(errno));
}
int
shcomexec(char **wp)
{
struct tbl *tp;
tp = ktsearch(&builtins, *wp, hash(*wp));
if (tp == NULL)
internal_errorf("%s: %s", __func__, *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, unsigned int h, int create)
{
struct block *l;
struct tbl *tp = NULL;
for (l = genv->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;
int was_set = 0;
while (1) {
tp = findfunc(name, hash(name), true);
if (tp->flag & ISSET)
was_set = 1;
/* 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) (char **))
{
struct tbl *tp;
int 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;
unsigned int h = hash(name);
struct tbl *tp = NULL, *tbi;
int insert = Flag(FTRACKALL); /* insert if not found */
char *fpath; /* for function autoloading */
char *npath;
if (strchr(name, '/') != NULL) {
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;
/* todo: posix says non-special/non-regular builtins must
* be triggered by some user-controllable means like a
* special directory in PATH. Requires modifications to
* the search() function. Tracked aliases should be
* modified to allow tracking of builtin commands.
* This should be under control of the FPOSIX flag.
* If this is changed, also change c_whence...
*/
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 = search(name, flags & FC_DEFPATH ? def_path :
search_path, X_OK, &tp->u2.errno_);
if (npath) {
if (tp == &temp) {
tp->val.s = npath;
} else {
tp->val.s = str_save(npath, APERM);
if (npath != name)
afree(npath, ATEMP);
}
tp->flag |= ISSET|ALLOC;
} else if ((flags & FC_FUNC) &&
(fpath = str_val(global("FPATH"))) != null &&
(npath = 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;
}
}
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 *path, int mode,
int *errnop) /* set if candidate found, but not suitable */
{
int ret, err = 0;
struct stat statb;
if (stat(path, &statb) == -1)
return -1;
ret = access(path, mode);
if (ret == -1)
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
*/
char *
search(const char *name, const char *path,
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 (strchr(name, '/')) {
if (search_access(name, mode, errnop) == 0)
return (char *) name;
return NULL;
}
namelen = strlen(name) + 1;
Xinit(xs, xp, 128, ATEMP);
sp = path;
while (sp != NULL) {