summaryrefslogtreecommitdiff
path: root/bin/sh/exec.c
diff options
context:
space:
mode:
Diffstat (limited to 'bin/sh/exec.c')
-rw-r--r--bin/sh/exec.c1183
1 files changed, 1183 insertions, 0 deletions
diff --git a/bin/sh/exec.c b/bin/sh/exec.c
new file mode 100644
index 0000000..674beb8
--- /dev/null
+++ b/bin/sh/exec.c
@@ -0,0 +1,1183 @@
+/* $NetBSD: exec.c,v 1.53 2018/07/25 14:42:50 kre Exp $ */
+
+/*-
+ * 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.
+ * 3. 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.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95";
+#else
+__RCSID("$NetBSD: exec.c,v 1.53 2018/07/25 14:42:50 kre Exp $");
+#endif
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.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 "init.h"
+#include "mystring.h"
+#include "show.h"
+#include "jobs.h"
+#include "alias.h"
+
+
+#define CMDTABLESIZE 31 /* should be prime */
+#define ARB 1 /* actual size determined at run time */
+
+
+
+struct tblentry {
+ struct tblentry *next; /* next entry in hash chain */
+ union param param; /* definition of builtin function */
+ short cmdtype; /* index identifying command */
+ char rehash; /* if set, cd done since entry created */
+ char fn_ln1; /* for functions, LINENO from 1 */
+ int lineno; /* for functions abs LINENO of definition */
+ char cmdname[ARB]; /* name of command */
+};
+
+
+STATIC struct tblentry *cmdtable[CMDTABLESIZE];
+STATIC int builtinloc = -1; /* index in path of %builtin, or -1 */
+int exerrno = 0; /* Last exec error */
+
+
+STATIC void tryexec(char *, char **, char **, int);
+STATIC void printentry(struct tblentry *, int);
+STATIC void addcmdentry(char *, struct cmdentry *);
+STATIC void clearcmdentry(int);
+STATIC struct tblentry *cmdlookup(const char *, int);
+STATIC void delete_cmd_entry(void);
+
+#ifndef BSD
+STATIC void execinterp(char **, char **);
+#endif
+
+
+extern const char *const parsekwd[];
+
+/*
+ * Exec a program. Never returns. If you change this routine, you may
+ * have to change the find_command routine as well.
+ */
+
+void
+shellexec(char **argv, char **envp, const char *path, int idx, int vforked)
+{
+ char *cmdname;
+ int e;
+
+ if (strchr(argv[0], '/') != NULL) {
+ tryexec(argv[0], argv, envp, vforked);
+ e = errno;
+ } else {
+ e = ENOENT;
+ while ((cmdname = padvance(&path, argv[0], 1)) != NULL) {
+ if (--idx < 0 && pathopt == NULL) {
+ tryexec(cmdname, argv, envp, vforked);
+ if (errno != ENOENT && errno != ENOTDIR)
+ e = errno;
+ }
+ stunalloc(cmdname);
+ }
+ }
+
+ /* Map to POSIX errors */
+ switch (e) {
+ case EACCES: /* particularly this (unless no search perm) */
+ /*
+ * should perhaps check if this EACCES is an exec()
+ * EACESS or a namei() EACESS - the latter should be 127
+ * - but not today
+ */
+ case EINVAL: /* also explicitly these */
+ case ENOEXEC:
+ default: /* and anything else */
+ exerrno = 126;
+ break;
+
+ case ENOENT: /* these are the "pathname lookup failed" errors */
+ case ELOOP:
+ case ENOTDIR:
+ case ENAMETOOLONG:
+ exerrno = 127;
+ break;
+ }
+ CTRACE(DBG_ERRS|DBG_CMDS|DBG_EVAL,
+ ("shellexec failed for %s, errno %d, vforked %d, suppressint %d\n",
+ argv[0], e, vforked, suppressint));
+ exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC));
+ /* NOTREACHED */
+}
+
+
+STATIC void
+tryexec(char *cmd, char **argv, char **envp, int vforked)
+{
+ int e;
+#ifndef BSD
+ char *p;
+#endif
+
+#ifdef SYSV
+ do {
+ execve(cmd, argv, envp);
+ } while (errno == EINTR);
+#else
+ execve(cmd, argv, envp);
+#endif
+ e = errno;
+ if (e == ENOEXEC) {
+ if (vforked) {
+ /* We are currently vfork(2)ed, so raise an
+ * exception, and evalcommand will try again
+ * with a normal fork(2).
+ */
+ exraise(EXSHELLPROC);
+ }
+#ifdef DEBUG
+ VTRACE(DBG_CMDS, ("execve(cmd=%s) returned ENOEXEC\n", cmd));
+#endif
+ initshellproc();
+ setinputfile(cmd, 0);
+ commandname = arg0 = savestr(argv[0]);
+#ifndef BSD
+ pgetc(); pungetc(); /* fill up input buffer */
+ p = parsenextc;
+ if (parsenleft > 2 && p[0] == '#' && p[1] == '!') {
+ argv[0] = cmd;
+ execinterp(argv, envp);
+ }
+#endif
+ setparam(argv + 1);
+ exraise(EXSHELLPROC);
+ }
+ errno = e;
+}
+
+
+#ifndef BSD
+/*
+ * Execute an interpreter introduced by "#!", for systems where this
+ * feature has not been built into the kernel. If the interpreter is
+ * the shell, return (effectively ignoring the "#!"). If the execution
+ * of the interpreter fails, exit.
+ *
+ * This code peeks inside the input buffer in order to avoid actually
+ * reading any input. It would benefit from a rewrite.
+ */
+
+#define NEWARGS 5
+
+STATIC void
+execinterp(char **argv, char **envp)
+{
+ int n;
+ char *inp;
+ char *outp;
+ char c;
+ char *p;
+ char **ap;
+ char *newargs[NEWARGS];
+ int i;
+ char **ap2;
+ char **new;
+
+ n = parsenleft - 2;
+ inp = parsenextc + 2;
+ ap = newargs;
+ for (;;) {
+ while (--n >= 0 && (*inp == ' ' || *inp == '\t'))
+ inp++;
+ if (n < 0)
+ goto bad;
+ if ((c = *inp++) == '\n')
+ break;
+ if (ap == &newargs[NEWARGS])
+bad: error("Bad #! line");
+ STARTSTACKSTR(outp);
+ do {
+ STPUTC(c, outp);
+ } while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n');
+ STPUTC('\0', outp);
+ n++, inp--;
+ *ap++ = grabstackstr(outp);
+ }
+ if (ap == newargs + 1) { /* if no args, maybe no exec is needed */
+ p = newargs[0];
+ for (;;) {
+ if (equal(p, "sh") || equal(p, "ash")) {
+ return;
+ }
+ while (*p != '/') {
+ if (*p == '\0')
+ goto break2;
+ p++;
+ }
+ p++;
+ }
+break2:;
+ }
+ i = (char *)ap - (char *)newargs; /* size in bytes */
+ if (i == 0)
+ error("Bad #! line");
+ for (ap2 = argv ; *ap2++ != NULL ; );
+ new = ckmalloc(i + ((char *)ap2 - (char *)argv));
+ ap = newargs, ap2 = new;
+ while ((i -= sizeof (char **)) >= 0)
+ *ap2++ = *ap++;
+ ap = argv;
+ while (*ap2++ = *ap++);
+ shellexec(new, envp, pathval(), 0);
+ /* NOTREACHED */
+}
+#endif
+
+
+
+/*
+ * 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, int magic_percent)
+{
+ const char *p;
+ char *q;
+ const char *start;
+ int len;
+
+ if (*path == NULL)
+ return NULL;
+ if (magic_percent)
+ magic_percent = '%';
+
+ start = *path;
+ for (p = start ; *p && *p != ':' && *p != magic_percent ; p++)
+ ;
+ len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */
+ while (stackblocksize() < len)
+ growstackblock();
+ q = stackblock();
+ if (p != start) {
+ memcpy(q, start, p - start);
+ q += p - start;
+ if (q[-1] != '/')
+ *q++ = '/';
+ }
+ strcpy(q, name);
+ pathopt = NULL;
+ if (*p == magic_percent) {
+ pathopt = ++p;
+ while (*p && *p != ':')
+ p++;
+ }
+ if (*p == ':')
+ *path = p + 1;
+ else
+ *path = NULL;
+ return grabstackstr(q + strlen(name) + 1);
+}
+
+
+/*** Command hashing code ***/
+
+
+int
+hashcmd(int argc, char **argv)
+{
+ struct tblentry **pp;
+ struct tblentry *cmdp;
+ int c;
+ struct cmdentry entry;
+ char *name;
+ int allopt=0, bopt=0, fopt=0, ropt=0, sopt=0, uopt=0, verbose=0;
+
+ while ((c = nextopt("bcfrsuv")) != '\0')
+ switch (c) {
+ case 'b': bopt = 1; break;
+ case 'c': uopt = 1; break; /* c == u */
+ case 'f': fopt = 1; break;
+ case 'r': ropt = 1; break;
+ case 's': sopt = 1; break;
+ case 'u': uopt = 1; break;
+ case 'v': verbose = 1; break;
+ }
+
+ if (ropt)
+ clearcmdentry(0);
+
+ if (bopt == 0 && fopt == 0 && sopt == 0 && uopt == 0)
+ allopt = bopt = fopt = sopt = uopt = 1;
+
+ if (*argptr == NULL) {
+ for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+ for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+ switch (cmdp->cmdtype) {
+ case CMDNORMAL:
+ if (!uopt)
+ continue;
+ break;
+ case CMDBUILTIN:
+ if (!bopt)
+ continue;
+ break;
+ case CMDSPLBLTIN:
+ if (!sopt)
+ continue;
+ break;
+ case CMDFUNCTION:
+ if (!fopt)
+ continue;
+ break;
+ default: /* never happens */
+ continue;
+ }
+ if (!allopt || verbose ||
+ cmdp->cmdtype == CMDNORMAL)
+ printentry(cmdp, verbose);
+ }
+ }
+ return 0;
+ }
+
+ while ((name = *argptr++) != NULL) {
+ if ((cmdp = cmdlookup(name, 0)) != NULL) {
+ switch (cmdp->cmdtype) {
+ case CMDNORMAL:
+ if (!uopt)
+ continue;
+ delete_cmd_entry();
+ break;
+ case CMDBUILTIN:
+ if (!bopt)
+ continue;
+ if (builtinloc >= 0)
+ delete_cmd_entry();
+ break;
+ case CMDSPLBLTIN:
+ if (!sopt)
+ continue;
+ break;
+ case CMDFUNCTION:
+ if (!fopt)
+ continue;
+ break;
+ }
+ }
+ find_command(name, &entry, DO_ERR, pathval());
+ if (verbose) {
+ if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
+ cmdp = cmdlookup(name, 0);
+ if (cmdp != NULL)
+ printentry(cmdp, verbose);
+ }
+ flushall();
+ }
+ }
+ return 0;
+}
+
+STATIC void
+printentry(struct tblentry *cmdp, int verbose)
+{
+ int idx;
+ const char *path;
+ char *name;
+
+ switch (cmdp->cmdtype) {
+ case CMDNORMAL:
+ idx = cmdp->param.index;
+ path = pathval();
+ do {
+ name = padvance(&path, cmdp->cmdname, 1);
+ stunalloc(name);
+ } while (--idx >= 0);
+ if (verbose)
+ out1fmt("Command from PATH[%d]: ",
+ cmdp->param.index);
+ out1str(name);
+ break;
+ case CMDSPLBLTIN:
+ if (verbose)
+ out1str("special ");
+ /* FALLTHROUGH */
+ case CMDBUILTIN:
+ if (verbose)
+ out1str("builtin ");
+ out1fmt("%s", cmdp->cmdname);
+ break;
+ case CMDFUNCTION:
+ if (verbose)
+ out1str("function ");
+ out1fmt("%s", cmdp->cmdname);
+ if (verbose) {
+ struct procstat ps;
+
+ INTOFF;
+ commandtext(&ps, getfuncnode(cmdp->param.func));
+ INTON;
+ out1str("() { ");
+ out1str(ps.cmd);
+ out1str("; }");
+ }
+ break;
+ default:
+ error("internal error: %s cmdtype %d",
+ cmdp->cmdname, cmdp->cmdtype);
+ }
+ if (cmdp->rehash)
+ out1c('*');
+ out1c('\n');
+}
+
+
+
+/*
+ * Resolve a command name. If you change this routine, you may have to
+ * change the shellexec routine as well.
+ */
+
+void
+find_command(char *name, struct cmdentry *entry, int act, const char *path)
+{
+ struct tblentry *cmdp, loc_cmd;
+ int idx;
+ int prev;
+ char *fullname;
+ struct stat statb;
+ int e;
+ int (*bltin)(int,char **);
+
+ /* If name contains a slash, don't use PATH or hash table */
+ if (strchr(name, '/') != NULL) {
+ if (act & DO_ABS) {
+ while (stat(name, &statb) < 0) {
+#ifdef SYSV
+ if (errno == EINTR)
+ continue;
+#endif
+ if (errno != ENOENT && errno != ENOTDIR)
+ e = errno;
+ entry->cmdtype = CMDUNKNOWN;
+ entry->u.index = -1;
+ return;
+ }
+ entry->cmdtype = CMDNORMAL;
+ entry->u.index = -1;
+ return;
+ }
+ entry->cmdtype = CMDNORMAL;
+ entry->u.index = 0;
+ return;
+ }
+
+ if (path != pathval())
+ act |= DO_ALTPATH;
+
+ if (act & DO_ALTPATH && strstr(path, "%builtin") != NULL)
+ act |= DO_ALTBLTIN;
+
+ /* If name is in the table, check answer will be ok */
+ if ((cmdp = cmdlookup(name, 0)) != NULL) {
+ do {
+ switch (cmdp->cmdtype) {
+ case CMDNORMAL:
+ if (act & DO_ALTPATH) {
+ cmdp = NULL;
+ continue;
+ }
+ break;
+ case CMDFUNCTION:
+ if (act & DO_NOFUNC) {
+ cmdp = NULL;
+ continue;
+ }
+ break;
+ case CMDBUILTIN:
+ if ((act & DO_ALTBLTIN) || builtinloc >= 0) {
+ cmdp = NULL;
+ continue;
+ }
+ break;
+ }
+ /* if not invalidated by cd, we're done */
+ if (cmdp->rehash == 0)
+ goto success;
+ } while (0);
+ }
+
+ /* If %builtin not in path, check for builtin next */
+ if ((act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc < 0) &&
+ (bltin = find_builtin(name)) != 0)
+ goto builtin_success;
+
+ /* We have to search path. */
+ prev = -1; /* where to start */
+ if (cmdp) { /* doing a rehash */
+ if (cmdp->cmdtype == CMDBUILTIN)
+ prev = builtinloc;
+ else
+ prev = cmdp->param.index;
+ }
+
+ e = ENOENT;
+ idx = -1;
+loop:
+ while ((fullname = padvance(&path, name, 1)) != NULL) {
+ stunalloc(fullname);
+ idx++;
+ if (pathopt) {
+ if (prefix("builtin", pathopt)) {
+ if ((bltin = find_builtin(name)) == 0)
+ goto loop;
+ goto builtin_success;
+ } else if (prefix("func", pathopt)) {
+ /* handled below */
+ } else {
+ /* ignore unimplemented options */
+ goto loop;
+ }
+ }
+ /* if rehash, don't redo absolute path names */
+ if (fullname[0] == '/' && idx <= prev) {
+ if (idx < prev)
+ goto loop;
+ VTRACE(DBG_CMDS, ("searchexec \"%s\": no change\n",
+ name));
+ goto success;
+ }
+ while (stat(fullname, &statb) < 0) {
+#ifdef SYSV
+ if (errno == EINTR)
+ continue;
+#endif
+ 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 */
+ char *endname;
+
+ if (act & DO_NOFUNC)
+ goto loop;
+ endname = fullname + strlen(fullname) + 1;
+ grabstackstr(endname);
+ readcmdfile(fullname);
+ if ((cmdp = cmdlookup(name, 0)) == NULL ||
+ cmdp->cmdtype != CMDFUNCTION)
+ error("%s not defined in %s", name, fullname);
+ ungrabstackstr(fullname, endname);
+ goto success;
+ }
+#ifdef notdef
+ /* XXX this code stops root executing stuff, and is buggy
+ if you need a group from the group list. */
+ 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
+ VTRACE(DBG_CMDS, ("searchexec \"%s\" returns \"%s\"\n", name,
+ fullname));
+ INTOFF;
+ if (act & DO_ALTPATH) {
+ /*
+ * this should be a grabstackstr() but is not needed:
+ * fullname is no longer needed for anything
+ stalloc(strlen(fullname) + 1);
+ */
+ cmdp = &loc_cmd;
+ } else
+ cmdp = cmdlookup(name, 1);
+ cmdp->cmdtype = CMDNORMAL;
+ cmdp->param.index = idx;
+ INTON;
+ goto success;
+ }
+
+ /* We failed. If there was an entry for this command, delete it */
+ if (cmdp)
+ delete_cmd_entry();
+ if (act & DO_ERR)
+ outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
+ entry->cmdtype = CMDUNKNOWN;
+ return;
+
+builtin_success:
+ INTOFF;
+ if (act & DO_ALTPATH)
+ cmdp = &loc_cmd;
+ else
+ cmdp = cmdlookup(name, 1);
+ if (cmdp->cmdtype == CMDFUNCTION)
+ /* DO_NOFUNC must have been set */
+ cmdp = &loc_cmd;
+ cmdp->cmdtype = CMDBUILTIN;
+ cmdp->param.bltin = bltin;
+ INTON;
+success:
+ if (cmdp) {
+ cmdp->rehash = 0;
+ entry->cmdtype = cmdp->cmdtype;
+ entry->lineno = cmdp->lineno;
+ entry->lno_frel = cmdp->fn_ln1;
+ entry->u = cmdp->param;
+ } else
+ entry->cmdtype = CMDUNKNOWN;
+}
+
+
+
+/*
+ * Search the table of builtin commands.
+ */
+
+int
+(*find_builtin(char *name))(int, char **)
+{
+ const struct builtincmd *bp;
+
+ for (bp = builtincmd ; bp->name ; bp++) {
+ if (*bp->name == *name
+ && (*name == '%' || equal(bp->name, name)))
+ return bp->builtin;
+ }
+ return 0;
+}
+
+int
+(*find_splbltin(char *name))(int, char **)
+{
+ const struct builtincmd *bp;
+
+ for (bp = splbltincmd ; bp->name ; bp++) {
+ if (*bp->name == *name && equal(bp->name, name))
+ return bp->builtin;
+ }
+ return 0;
+}
+
+/*
+ * At shell startup put special builtins into hash table.
+ * ensures they are executed first (see posix).
+ * We stop functions being added with the same name
+ * (as they are impossible to call)
+ */
+
+void
+hash_special_builtins(void)
+{
+ const struct builtincmd *bp;
+ struct tblentry *cmdp;
+
+ for (bp = splbltincmd ; bp->name ; bp++) {
+ cmdp = cmdlookup(bp->name, 1);
+ cmdp->cmdtype = CMDSPLBLTIN;
+ cmdp->param.bltin = bp->builtin;
+ }
+}
+
+
+
+/*
+ * Called when a cd is done. Marks all commands so the next time they
+ * are executed they will be rehashed.
+ */
+
+void
+hashcd(void)
+{
+ struct tblentry **pp;
+ struct tblentry *cmdp;
+
+ for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+ for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+ if (cmdp->cmdtype == CMDNORMAL
+ || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
+ cmdp->rehash = 1;
+ }
+ }
+}
+
+
+
+/*
+ * Fix command hash table when PATH changed.
+ * 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)
+{
+ const char *old, *new;
+ int idx;
+ int firstchange;
+ int bltin;
+
+ old = pathval();
+ new = newval;
+ firstchange = 9999; /* assume no change */
+ idx = 0;
+ bltin = -1;
+ for (;;) {
+ if (*old != *new) {
+ firstchange = idx;
+ if ((*old == '\0' && *new == ':')
+ || (*old == ':' && *new == '\0'))
+ firstchange++;
+ old = new; /* ignore subsequent differences */
+ }
+ if (*new == '\0')
+ break;
+ if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
+ bltin = idx;
+ if (*new == ':') {
+ idx++;
+ }
+ new++, old++;
+ }
+ if (builtinloc < 0 && bltin >= 0)
+ builtinloc = bltin; /* zap builtins */
+ if (builtinloc >= 0 && bltin < 0)
+ firstchange = 0;
+ clearcmdentry(firstchange);
+ builtinloc = bltin;
+}
+
+
+/*
+ * Clear out command entries. The argument specifies the first entry in
+ * PATH which has changed.
+ */
+
+STATIC void
+clearcmdentry(int firstchange)
+{
+ 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 &&
+ cmdp->param.index >= firstchange)
+ || (cmdp->cmdtype == CMDBUILTIN &&
+ builtinloc >= firstchange)) {
+ *pp = cmdp->next;
+ ckfree(cmdp);
+ } else {
+ pp = &cmdp->next;
+ }
+ }
+ }
+ INTON;
+}
+
+
+/*
+ * Delete all functions.
+ */
+
+#ifdef mkinit
+MKINIT void deletefuncs(void);
+MKINIT void hash_special_builtins(void);
+
+INIT {
+ hash_special_builtins();
+}
+
+SHELLPROC {
+ deletefuncs();
+}
+#endif
+
+void
+deletefuncs(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 == CMDFUNCTION) {
+ *pp = cmdp->next;
+ freefunc(cmdp->param.func);
+ ckfree(cmdp);
+ } else {
+ pp = &cmdp->next;
+ }
+ }
+ }
+ 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.
+ */
+
+struct tblentry **lastcmdentry;
+
+
+STATIC struct tblentry *
+cmdlookup(const char *name, int add)
+{
+ int hashval;
+ const char *p;
+ struct tblentry *cmdp;
+ struct tblentry **pp;
+
+ 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;
+ cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
+ + strlen(name) + 1);
+ cmdp->next = NULL;
+ cmdp->cmdtype = CMDUNKNOWN;
+ cmdp->rehash = 0;
+ strcpy(cmdp->cmdname, name);
+ 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;
+}
+
+
+
+#ifdef notdef
+void
+getcmdentry(char *name, struct cmdentry *entry)
+{
+ struct tblentry *cmdp = cmdlookup(name, 0);
+
+ if (cmdp) {
+ entry->u = cmdp->param;
+ entry->cmdtype = cmdp->cmdtype;
+ } else {
+ entry->cmdtype = CMDUNKNOWN;
+ entry->u.index = 0;
+ }
+}
+#endif
+
+
+/*
+ * Add a new command entry, replacing any existing command entry for
+ * the same name - except special builtins.
+ */
+
+STATIC void
+addcmdentry(char *name, struct cmdentry *entry)
+{
+ struct tblentry *cmdp;
+
+ INTOFF;
+ cmdp = cmdlookup(name, 1);
+ if (cmdp->cmdtype != CMDSPLBLTIN) {
+ if (cmdp->cmdtype == CMDFUNCTION)
+ unreffunc(cmdp->param.func);
+ cmdp->cmdtype = entry->cmdtype;
+ cmdp->lineno = entry->lineno;
+ cmdp->fn_ln1 = entry->lno_frel;
+ cmdp->param = entry->u;
+ }
+ INTON;
+}
+
+
+/*
+ * Define a shell function.
+ */
+
+void
+defun(char *name, union node *func, int lineno)
+{
+ struct cmdentry entry;
+
+ INTOFF;
+ entry.cmdtype = CMDFUNCTION;
+ entry.lineno = lineno;
+ entry.lno_frel = fnline1;
+ entry.u.func = copyfunc(func);
+ addcmdentry(name, &entry);
+ INTON;
+}
+
+
+/*
+ * Delete a function if it exists.
+ */
+
+int
+unsetfunc(char *name)
+{
+ struct tblentry *cmdp;
+
+ if ((cmdp = cmdlookup(name, 0)) != NULL &&
+ cmdp->cmdtype == CMDFUNCTION) {
+ unreffunc(cmdp->param.func);
+ delete_cmd_entry();
+ }
+ return 0;
+}
+
+/*
+ * Locate and print what a word is...
+ * also used for 'command -[v|V]'
+ */
+
+int
+typecmd(int argc, char **argv)
+{
+ struct cmdentry entry;
+ struct tblentry *cmdp;
+ const char * const *pp;
+ struct alias *ap;
+ int err = 0;
+ char *arg;
+ int c;
+ int V_flag = 0;
+ int v_flag = 0;
+ int p_flag = 0;
+
+ while ((c = nextopt("vVp")) != 0) {
+ switch (c) {
+ case 'v': v_flag = 1; break;
+ case 'V': V_flag = 1; break;
+ case 'p': p_flag = 1; break;
+ }
+ }
+
+ if (argv[0][0] != 'c' && v_flag | V_flag | p_flag)
+ error("usage: %s name...", argv[0]);
+
+ if (v_flag && V_flag)
+ error("-v and -V cannot both be specified");
+
+ if (*argptr == NULL)
+ error("usage: %s%s name ...", argv[0],
+ argv[0][0] == 'c' ? " [-p] [-v|-V]" : "");
+
+ while ((arg = *argptr++)) {
+ if (!v_flag)
+ out1str(arg);
+ /* First look at the keywords */
+ for (pp = parsekwd; *pp; pp++)
+ if (**pp == *arg && equal(*pp, arg))
+ break;
+
+ if (*pp) {
+ if (v_flag)
+ out1fmt("%s\n", arg);
+ else
+ out1str(" is a shell keyword\n");
+ continue;
+ }
+
+ /* Then look at the aliases */
+ if ((ap = lookupalias(arg, 1)) != NULL) {
+ int ml = 0;
+
+ if (!v_flag) {
+ out1str(" is an alias ");
+ if (strchr(ap->val, '\n')) {
+ out1str("(multiline)...\n");
+ ml = 1;
+ } else
+ out1str("for: ");
+ }
+ out1fmt("%s\n", ap->val);
+ if (ml && *argptr != NULL)
+ out1c('\n');
+ continue;
+ }
+
+ /* Then check if it is a tracked alias */
+ if (!p_flag && (cmdp = cmdlookup(arg, 0)) != NULL) {
+ entry.cmdtype = cmdp->cmdtype;
+ entry.u = cmdp->param;
+ } else {
+ cmdp = NULL;
+ /* Finally use brute force */
+ find_command(arg, &entry, DO_ABS,
+ p_flag ? syspath() + 5 : pathval());
+ }
+
+ switch (entry.cmdtype) {
+ case CMDNORMAL: {
+ if (strchr(arg, '/') == NULL) {
+ const char *path;
+ char *name;
+ int j = entry.u.index;
+
+ path = p_flag ? syspath() + 5 : pathval();
+
+ do {
+ name = padvance(&path, arg, 1);
+ stunalloc(name);
+ } while (--j >= 0);
+ if (!v_flag)
+ out1fmt(" is%s ",
+ cmdp ? " a tracked alias for" : "");
+ out1fmt("%s\n", name);
+ } else {
+ if (access(arg, X_OK) == 0) {
+ if (!v_flag)
+ out1fmt(" is ");
+ out1fmt("%s\n", arg);
+ } else {
+ if (!v_flag)
+ out1fmt(": %s\n",
+ strerror(errno));
+ else
+ err = 126;
+ }
+ }
+ break;
+ }
+ case CMDFUNCTION:
+ if (!v_flag)
+ out1str(" is a shell function\n");
+ else
+ out1fmt("%s\n", arg);
+ break;
+
+ case CMDBUILTIN:
+ if (!v_flag)
+ out1str(" is a shell builtin\n");
+ else
+ out1fmt("%s\n", arg);
+ break;
+
+ case CMDSPLBLTIN:
+ if (!v_flag)
+ out1str(" is a special shell builtin\n");
+ else
+ out1fmt("%s\n", arg);
+ break;
+
+ default:
+ if (!v_flag)
+ out1str(": not found\n");
+ err = 127;
+ break;
+ }
+ }
+ return err;
+}
generated by cgit v1.2.3-60-g2f50 (git 2.42.0) at 2024-06-28 22:00:35 +0000