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-rw-r--r--bin/sh/exec.c773
1 files changed, 773 insertions, 0 deletions
diff --git a/bin/sh/exec.c b/bin/sh/exec.c
new file mode 100644
index 000000000000..e547e3136658
--- /dev/null
+++ b/bin/sh/exec.c
@@ -0,0 +1,773 @@
+/*-
+ * Copyright (c) 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95";
+#endif
+#endif /* not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <paths.h>
+#include <stdlib.h>
+
+/*
+ * When commands are first encountered, they are entered in a hash table.
+ * This ensures that a full path search will not have to be done for them
+ * on each invocation.
+ *
+ * We should investigate converting to a linear search, even though that
+ * would make the command name "hash" a misnomer.
+ */
+
+#include "shell.h"
+#include "main.h"
+#include "nodes.h"
+#include "parser.h"
+#include "redir.h"
+#include "eval.h"
+#include "exec.h"
+#include "builtins.h"
+#include "var.h"
+#include "options.h"
+#include "input.h"
+#include "output.h"
+#include "syntax.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mystring.h"
+#include "show.h"
+#include "jobs.h"
+#include "alias.h"
+
+
+#define CMDTABLESIZE 31 /* should be prime */
+
+
+
+struct tblentry {
+ struct tblentry *next; /* next entry in hash chain */
+ union param param; /* definition of builtin function */
+ int special; /* flag for special builtin commands */
+ signed char cmdtype; /* index identifying command */
+ char cmdname[]; /* name of command */
+};
+
+
+static struct tblentry *cmdtable[CMDTABLESIZE];
+static int cmdtable_cd = 0; /* cmdtable contains cd-dependent entries */
+int exerrno = 0; /* Last exec error */
+
+
+static void tryexec(char *, char **, char **);
+static void printentry(struct tblentry *, int);
+static struct tblentry *cmdlookup(const char *, int);
+static void delete_cmd_entry(void);
+static void addcmdentry(const char *, struct cmdentry *);
+
+
+
+/*
+ * Exec a program. Never returns. If you change this routine, you may
+ * have to change the find_command routine as well.
+ *
+ * The argv array may be changed and element argv[-1] should be writable.
+ */
+
+void
+shellexec(char **argv, char **envp, const char *path, int idx)
+{
+ char *cmdname;
+ int e;
+
+ if (strchr(argv[0], '/') != NULL) {
+ tryexec(argv[0], argv, envp);
+ e = errno;
+ } else {
+ e = ENOENT;
+ while ((cmdname = padvance(&path, argv[0])) != NULL) {
+ if (--idx < 0 && pathopt == NULL) {
+ tryexec(cmdname, argv, envp);
+ if (errno != ENOENT && errno != ENOTDIR)
+ e = errno;
+ if (e == ENOEXEC)
+ break;
+ }
+ stunalloc(cmdname);
+ }
+ }
+
+ /* Map to POSIX errors */
+ if (e == ENOENT || e == ENOTDIR) {
+ exerrno = 127;
+ exerror(EXEXEC, "%s: not found", argv[0]);
+ } else {
+ exerrno = 126;
+ exerror(EXEXEC, "%s: %s", argv[0], strerror(e));
+ }
+}
+
+
+static void
+tryexec(char *cmd, char **argv, char **envp)
+{
+ int e, in;
+ ssize_t n;
+ char buf[256];
+
+ execve(cmd, argv, envp);
+ e = errno;
+ if (e == ENOEXEC) {
+ INTOFF;
+ in = open(cmd, O_RDONLY | O_NONBLOCK);
+ if (in != -1) {
+ n = pread(in, buf, sizeof buf, 0);
+ close(in);
+ if (n > 0 && memchr(buf, '\0', n) != NULL) {
+ errno = ENOEXEC;
+ return;
+ }
+ }
+ *argv = cmd;
+ *--argv = __DECONST(char *, _PATH_BSHELL);
+ execve(_PATH_BSHELL, argv, envp);
+ }
+ errno = e;
+}
+
+/*
+ * Do a path search. The variable path (passed by reference) should be
+ * set to the start of the path before the first call; padvance will update
+ * this value as it proceeds. Successive calls to padvance will return
+ * the possible path expansions in sequence. If an option (indicated by
+ * a percent sign) appears in the path entry then the global variable
+ * pathopt will be set to point to it; otherwise pathopt will be set to
+ * NULL.
+ */
+
+const char *pathopt;
+
+char *
+padvance(const char **path, const char *name)
+{
+ const char *p, *start;
+ char *q;
+ size_t len, namelen;
+
+ if (*path == NULL)
+ return NULL;
+ start = *path;
+ for (p = start; *p && *p != ':' && *p != '%'; p++)
+ ; /* nothing */
+ namelen = strlen(name);
+ len = p - start + namelen + 2; /* "2" is for '/' and '\0' */
+ STARTSTACKSTR(q);
+ CHECKSTRSPACE(len, q);
+ if (p != start) {
+ memcpy(q, start, p - start);
+ q += p - start;
+ *q++ = '/';
+ }
+ memcpy(q, name, namelen + 1);
+ pathopt = NULL;
+ if (*p == '%') {
+ pathopt = ++p;
+ while (*p && *p != ':') p++;
+ }
+ if (*p == ':')
+ *path = p + 1;
+ else
+ *path = NULL;
+ return stalloc(len);
+}
+
+
+
+/*** Command hashing code ***/
+
+
+int
+hashcmd(int argc __unused, char **argv __unused)
+{
+ struct tblentry **pp;
+ struct tblentry *cmdp;
+ int c;
+ int verbose;
+ struct cmdentry entry;
+ char *name;
+ int errors;
+
+ errors = 0;
+ verbose = 0;
+ while ((c = nextopt("rv")) != '\0') {
+ if (c == 'r') {
+ clearcmdentry();
+ } else if (c == 'v') {
+ verbose++;
+ }
+ }
+ if (*argptr == NULL) {
+ for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+ for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+ if (cmdp->cmdtype == CMDNORMAL)
+ printentry(cmdp, verbose);
+ }
+ }
+ return 0;
+ }
+ while ((name = *argptr) != NULL) {
+ if ((cmdp = cmdlookup(name, 0)) != NULL
+ && cmdp->cmdtype == CMDNORMAL)
+ delete_cmd_entry();
+ find_command(name, &entry, DO_ERR, pathval());
+ if (entry.cmdtype == CMDUNKNOWN)
+ errors = 1;
+ else if (verbose) {
+ cmdp = cmdlookup(name, 0);
+ if (cmdp != NULL)
+ printentry(cmdp, verbose);
+ else {
+ outfmt(out2, "%s: not found\n", name);
+ errors = 1;
+ }
+ flushall();
+ }
+ argptr++;
+ }
+ return errors;
+}
+
+
+static void
+printentry(struct tblentry *cmdp, int verbose)
+{
+ int idx;
+ const char *path;
+ char *name;
+
+ if (cmdp->cmdtype == CMDNORMAL) {
+ idx = cmdp->param.index;
+ path = pathval();
+ do {
+ name = padvance(&path, cmdp->cmdname);
+ stunalloc(name);
+ } while (--idx >= 0);
+ out1str(name);
+ } else if (cmdp->cmdtype == CMDBUILTIN) {
+ out1fmt("builtin %s", cmdp->cmdname);
+ } else if (cmdp->cmdtype == CMDFUNCTION) {
+ out1fmt("function %s", cmdp->cmdname);
+ if (verbose) {
+ INTOFF;
+ name = commandtext(getfuncnode(cmdp->param.func));
+ out1c(' ');
+ out1str(name);
+ ckfree(name);
+ INTON;
+ }
+#ifdef DEBUG
+ } else {
+ error("internal error: cmdtype %d", cmdp->cmdtype);
+#endif
+ }
+ out1c('\n');
+}
+
+
+
+/*
+ * Resolve a command name. If you change this routine, you may have to
+ * change the shellexec routine as well.
+ */
+
+void
+find_command(const char *name, struct cmdentry *entry, int act,
+ const char *path)
+{
+ struct tblentry *cmdp, loc_cmd;
+ int idx;
+ char *fullname;
+ struct stat statb;
+ int e;
+ int i;
+ int spec;
+ int cd;
+
+ /* If name contains a slash, don't use the hash table */
+ if (strchr(name, '/') != NULL) {
+ entry->cmdtype = CMDNORMAL;
+ entry->u.index = 0;
+ return;
+ }
+
+ cd = 0;
+
+ /* If name is in the table, and not invalidated by cd, we're done */
+ if ((cmdp = cmdlookup(name, 0)) != NULL) {
+ if (cmdp->cmdtype == CMDFUNCTION && act & DO_NOFUNC)
+ cmdp = NULL;
+ else
+ goto success;
+ }
+
+ /* Check for builtin next */
+ if ((i = find_builtin(name, &spec)) >= 0) {
+ INTOFF;
+ cmdp = cmdlookup(name, 1);
+ if (cmdp->cmdtype == CMDFUNCTION)
+ cmdp = &loc_cmd;
+ cmdp->cmdtype = CMDBUILTIN;
+ cmdp->param.index = i;
+ cmdp->special = spec;
+ INTON;
+ goto success;
+ }
+
+ /* We have to search path. */
+
+ e = ENOENT;
+ idx = -1;
+loop:
+ while ((fullname = padvance(&path, name)) != NULL) {
+ stunalloc(fullname);
+ idx++;
+ if (pathopt) {
+ if (prefix("func", pathopt)) {
+ /* handled below */
+ } else {
+ goto loop; /* ignore unimplemented options */
+ }
+ }
+ if (fullname[0] != '/')
+ cd = 1;
+ if (stat(fullname, &statb) < 0) {
+ if (errno != ENOENT && errno != ENOTDIR)
+ e = errno;
+ goto loop;
+ }
+ e = EACCES; /* if we fail, this will be the error */
+ if (!S_ISREG(statb.st_mode))
+ goto loop;
+ if (pathopt) { /* this is a %func directory */
+ stalloc(strlen(fullname) + 1);
+ readcmdfile(fullname);
+ if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION)
+ error("%s not defined in %s", name, fullname);
+ stunalloc(fullname);
+ goto success;
+ }
+#ifdef notdef
+ if (statb.st_uid == geteuid()) {
+ if ((statb.st_mode & 0100) == 0)
+ goto loop;
+ } else if (statb.st_gid == getegid()) {
+ if ((statb.st_mode & 010) == 0)
+ goto loop;
+ } else {
+ if ((statb.st_mode & 01) == 0)
+ goto loop;
+ }
+#endif
+ TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
+ INTOFF;
+ cmdp = cmdlookup(name, 1);
+ if (cmdp->cmdtype == CMDFUNCTION)
+ cmdp = &loc_cmd;
+ cmdp->cmdtype = CMDNORMAL;
+ cmdp->param.index = idx;
+ INTON;
+ goto success;
+ }
+
+ if (act & DO_ERR) {
+ if (e == ENOENT || e == ENOTDIR)
+ outfmt(out2, "%s: not found\n", name);
+ else
+ outfmt(out2, "%s: %s\n", name, strerror(e));
+ }
+ entry->cmdtype = CMDUNKNOWN;
+ entry->u.index = 0;
+ return;
+
+success:
+ if (cd)
+ cmdtable_cd = 1;
+ entry->cmdtype = cmdp->cmdtype;
+ entry->u = cmdp->param;
+ entry->special = cmdp->special;
+}
+
+
+
+/*
+ * Search the table of builtin commands.
+ */
+
+int
+find_builtin(const char *name, int *special)
+{
+ const struct builtincmd *bp;
+
+ for (bp = builtincmd ; bp->name ; bp++) {
+ if (*bp->name == *name && equal(bp->name, name)) {
+ *special = bp->special;
+ return bp->code;
+ }
+ }
+ return -1;
+}
+
+
+
+/*
+ * Called when a cd is done. If any entry in cmdtable depends on the current
+ * directory, simply clear cmdtable completely.
+ */
+
+void
+hashcd(void)
+{
+ if (cmdtable_cd)
+ clearcmdentry();
+}
+
+
+
+/*
+ * Called before PATH is changed. The argument is the new value of PATH;
+ * pathval() still returns the old value at this point. Called with
+ * interrupts off.
+ */
+
+void
+changepath(const char *newval __unused)
+{
+ clearcmdentry();
+}
+
+
+/*
+ * Clear out command entries. The argument specifies the first entry in
+ * PATH which has changed.
+ */
+
+void
+clearcmdentry(void)
+{
+ struct tblentry **tblp;
+ struct tblentry **pp;
+ struct tblentry *cmdp;
+
+ INTOFF;
+ for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
+ pp = tblp;
+ while ((cmdp = *pp) != NULL) {
+ if (cmdp->cmdtype == CMDNORMAL) {
+ *pp = cmdp->next;
+ ckfree(cmdp);
+ } else {
+ pp = &cmdp->next;
+ }
+ }
+ }
+ cmdtable_cd = 0;
+ INTON;
+}
+
+
+/*
+ * Locate a command in the command hash table. If "add" is nonzero,
+ * add the command to the table if it is not already present. The
+ * variable "lastcmdentry" is set to point to the address of the link
+ * pointing to the entry, so that delete_cmd_entry can delete the
+ * entry.
+ */
+
+static struct tblentry **lastcmdentry;
+
+
+static struct tblentry *
+cmdlookup(const char *name, int add)
+{
+ int hashval;
+ const char *p;
+ struct tblentry *cmdp;
+ struct tblentry **pp;
+ size_t len;
+
+ p = name;
+ hashval = *p << 4;
+ while (*p)
+ hashval += *p++;
+ hashval &= 0x7FFF;
+ pp = &cmdtable[hashval % CMDTABLESIZE];
+ for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+ if (equal(cmdp->cmdname, name))
+ break;
+ pp = &cmdp->next;
+ }
+ if (add && cmdp == NULL) {
+ INTOFF;
+ len = strlen(name);
+ cmdp = *pp = ckmalloc(sizeof (struct tblentry) + len + 1);
+ cmdp->next = NULL;
+ cmdp->cmdtype = CMDUNKNOWN;
+ memcpy(cmdp->cmdname, name, len + 1);
+ INTON;
+ }
+ lastcmdentry = pp;
+ return cmdp;
+}
+
+/*
+ * Delete the command entry returned on the last lookup.
+ */
+
+static void
+delete_cmd_entry(void)
+{
+ struct tblentry *cmdp;
+
+ INTOFF;
+ cmdp = *lastcmdentry;
+ *lastcmdentry = cmdp->next;
+ ckfree(cmdp);
+ INTON;
+}
+
+
+
+/*
+ * Add a new command entry, replacing any existing command entry for
+ * the same name.
+ */
+
+static void
+addcmdentry(const char *name, struct cmdentry *entry)
+{
+ struct tblentry *cmdp;
+
+ INTOFF;
+ cmdp = cmdlookup(name, 1);
+ if (cmdp->cmdtype == CMDFUNCTION) {
+ unreffunc(cmdp->param.func);
+ }
+ cmdp->cmdtype = entry->cmdtype;
+ cmdp->param = entry->u;
+ INTON;
+}
+
+
+/*
+ * Define a shell function.
+ */
+
+void
+defun(const char *name, union node *func)
+{
+ struct cmdentry entry;
+
+ INTOFF;
+ entry.cmdtype = CMDFUNCTION;
+ entry.u.func = copyfunc(func);
+ addcmdentry(name, &entry);
+ INTON;
+}
+
+
+/*
+ * Delete a function if it exists.
+ * Called with interrupts off.
+ */
+
+int
+unsetfunc(const char *name)
+{
+ struct tblentry *cmdp;
+
+ if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) {
+ unreffunc(cmdp->param.func);
+ delete_cmd_entry();
+ return (0);
+ }
+ return (0);
+}
+
+
+/*
+ * Check if a function by a certain name exists.
+ */
+int
+isfunc(const char *name)
+{
+ struct tblentry *cmdp;
+ cmdp = cmdlookup(name, 0);
+ return (cmdp != NULL && cmdp->cmdtype == CMDFUNCTION);
+}
+
+
+/*
+ * Shared code for the following builtin commands:
+ * type, command -v, command -V
+ */
+
+int
+typecmd_impl(int argc, char **argv, int cmd, const char *path)
+{
+ struct cmdentry entry;
+ struct tblentry *cmdp;
+ const char *const *pp;
+ struct alias *ap;
+ int i;
+ int error1 = 0;
+
+ if (path != pathval())
+ clearcmdentry();
+
+ for (i = 1; i < argc; i++) {
+ /* First look at the keywords */
+ for (pp = parsekwd; *pp; pp++)
+ if (**pp == *argv[i] && equal(*pp, argv[i]))
+ break;
+
+ if (*pp) {
+ if (cmd == TYPECMD_SMALLV)
+ out1fmt("%s\n", argv[i]);
+ else
+ out1fmt("%s is a shell keyword\n", argv[i]);
+ continue;
+ }
+
+ /* Then look at the aliases */
+ if ((ap = lookupalias(argv[i], 1)) != NULL) {
+ if (cmd == TYPECMD_SMALLV) {
+ out1fmt("alias %s=", argv[i]);
+ out1qstr(ap->val);
+ outcslow('\n', out1);
+ } else
+ out1fmt("%s is an alias for %s\n", argv[i],
+ ap->val);
+ continue;
+ }
+
+ /* Then check if it is a tracked alias */
+ if ((cmdp = cmdlookup(argv[i], 0)) != NULL) {
+ entry.cmdtype = cmdp->cmdtype;
+ entry.u = cmdp->param;
+ entry.special = cmdp->special;
+ }
+ else {
+ /* Finally use brute force */
+ find_command(argv[i], &entry, 0, path);
+ }
+
+ switch (entry.cmdtype) {
+ case CMDNORMAL: {
+ if (strchr(argv[i], '/') == NULL) {
+ const char *path2 = path;
+ char *name;
+ int j = entry.u.index;
+ do {
+ name = padvance(&path2, argv[i]);
+ stunalloc(name);
+ } while (--j >= 0);
+ if (cmd == TYPECMD_SMALLV)
+ out1fmt("%s\n", name);
+ else
+ out1fmt("%s is%s %s\n", argv[i],
+ (cmdp && cmd == TYPECMD_TYPE) ?
+ " a tracked alias for" : "",
+ name);
+ } else {
+ if (eaccess(argv[i], X_OK) == 0) {
+ if (cmd == TYPECMD_SMALLV)
+ out1fmt("%s\n", argv[i]);
+ else
+ out1fmt("%s is %s\n", argv[i],
+ argv[i]);
+ } else {
+ if (cmd != TYPECMD_SMALLV)
+ outfmt(out2, "%s: %s\n",
+ argv[i], strerror(errno));
+ error1 |= 127;
+ }
+ }
+ break;
+ }
+ case CMDFUNCTION:
+ if (cmd == TYPECMD_SMALLV)
+ out1fmt("%s\n", argv[i]);
+ else
+ out1fmt("%s is a shell function\n", argv[i]);
+ break;
+
+ case CMDBUILTIN:
+ if (cmd == TYPECMD_SMALLV)
+ out1fmt("%s\n", argv[i]);
+ else if (entry.special)
+ out1fmt("%s is a special shell builtin\n",
+ argv[i]);
+ else
+ out1fmt("%s is a shell builtin\n", argv[i]);
+ break;
+
+ default:
+ if (cmd != TYPECMD_SMALLV)
+ outfmt(out2, "%s: not found\n", argv[i]);
+ error1 |= 127;
+ break;
+ }
+ }
+
+ if (path != pathval())
+ clearcmdentry();
+
+ return error1;
+}
+
+/*
+ * Locate and print what a word is...
+ */
+
+int
+typecmd(int argc, char **argv)
+{
+ if (argc > 2 && strcmp(argv[1], "--") == 0)
+ argc--, argv++;
+ return typecmd_impl(argc, argv, TYPECMD_TYPE, bltinlookup("PATH", 1));
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-16 16:26:22 +0000