minix/commands/ash/exec.c
Lionel Sambuc 252a83f614 Fix command line history in ash
Also did some cleanup in ash sources, to make minix modifications
more obvious, as well as some simplifications (by removing code which
is never compiled)

Removed EDITLINE support, use libedit, which does the termcap/terminfo
handling.

Change-Id: I19f7f425ed6a61298844631f9d7f3173cf7f30c0
2013-02-01 11:41:47 +01:00

791 lines
16 KiB
C

/*-
* 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: src/bin/sh/exec.c,v 1.24.2.1 2004/09/30 04:41:55 des Exp $");
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.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 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 **);
STATIC void printentry(struct tblentry *, int);
STATIC struct tblentry *cmdlookup(char *, int);
STATIC void delete_cmd_entry(void);
STATIC void addcmdentry(char *, struct cmdentry *);
/*
* 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, char *path, int index)
{
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 (--index < 0 && pathopt == NULL) {
tryexec(cmdname, argv, envp);
if (errno != ENOENT && errno != ENOTDIR)
e = errno;
}
stunalloc(cmdname);
}
}
/* Map to POSIX errors */
switch (e) {
case EACCES:
exerrno = 126;
break;
case ENOENT:
exerrno = 127;
break;
default:
exerrno = 2;
break;
}
if (e == ENOENT || e == ENOTDIR)
exerror(EXEXEC, "%s: not found", argv[0]);
exerror(EXEXEC, "%s: %s", argv[0], strerror(e));
}
STATIC void
tryexec(char *cmd, char **argv, char **envp)
{
int e;
execve(cmd, argv, envp);
e = errno;
if (e == ENOEXEC) {
initshellproc();
setinputfile(cmd, 0);
commandname = arg0 = savestr(argv[0]);
setparam(argv + 1);
exraise(EXSHELLPROC);
/*NOTREACHED*/
}
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.
*/
char *pathopt;
char *
padvance(char **path, char *name)
{
char *p, *q;
char *start;
int len;
if (*path == NULL)
return NULL;
start = *path;
for (p = start ; *p && *p != ':' && *p != '%' ; 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;
*q++ = '/';
}
strcpy(q, name);
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;
verbose = 0;
while ((c = nextopt("rv")) != '\0') {
if (c == 'r') {
clearcmdentry(0);
} 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
|| (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
delete_cmd_entry();
find_command(name, &entry, 1, pathval());
if (verbose) {
if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
cmdp = cmdlookup(name, 0);
if (cmdp != NULL)
printentry(cmdp, verbose);
else
outfmt(&errout, "%s: not found\n", name);
}
flushall();
}
argptr++;
}
return 0;
}
STATIC void
printentry(struct tblentry *cmdp, int verbose)
{
int index;
char *path;
char *name;
if (cmdp->cmdtype == CMDNORMAL) {
index = cmdp->param.index;
path = pathval();
do {
name = padvance(&path, cmdp->cmdname);
stunalloc(name);
} while (--index >= 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(cmdp->param.func);
out1c(' ');
out1str(name);
ckfree(name);
INTON;
}
#if DEBUG
} else {
error("internal error: cmdtype %d", cmdp->cmdtype);
#endif
}
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 printerr, char *path)
{
struct tblentry *cmdp;
int index;
int prev;
char *fullname;
struct stat statb;
int e;
int i;
/* If name contains a slash, don't use the hash table */
if (strchr(name, '/') != NULL) {
entry->cmdtype = CMDNORMAL;
entry->u.index = 0;
return;
}
/* If name is in the table, and not invalidated by cd, we're done */
if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0)
goto success;
/* If %builtin not in path, check for builtin next */
if (builtinloc < 0 && (i = find_builtin(name)) >= 0) {
INTOFF;
cmdp = cmdlookup(name, 1);
cmdp->cmdtype = CMDBUILTIN;
cmdp->param.index = i;
INTON;
goto 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;
index = -1;
loop:
while ((fullname = padvance(&path, name)) != NULL) {
stunalloc(fullname);
index++;
if (pathopt) {
if (prefix("builtin", pathopt)) {
if ((i = find_builtin(name)) < 0)
goto loop;
INTOFF;
cmdp = cmdlookup(name, 1);
cmdp->cmdtype = CMDBUILTIN;
cmdp->param.index = i;
INTON;
goto success;
} else if (prefix("func", pathopt)) {
/* handled below */
} else {
goto loop; /* ignore unimplemented options */
}
}
/* if rehash, don't redo absolute path names */
if (fullname[0] == '/' && index <= prev) {
if (index < prev)
goto loop;
TRACE(("searchexec \"%s\": no change\n", name));
goto success;
}
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);
cmdp->cmdtype = CMDNORMAL;
cmdp->param.index = index;
INTON;
goto success;
}
/* We failed. If there was an entry for this command, delete it */
if (cmdp)
delete_cmd_entry();
if (printerr) {
if (e == ENOENT || e == ENOTDIR)
outfmt(out2, "%s: not found\n", name);
else
outfmt(out2, "%s: %s\n", name, strerror(e));
}
entry->cmdtype = CMDUNKNOWN;
return;
success:
cmdp->rehash = 0;
entry->cmdtype = cmdp->cmdtype;
entry->u = cmdp->param;
}
/*
* Search the table of builtin commands.
*/
int
find_builtin(char *name)
{
const struct builtincmd *bp;
for (bp = builtincmd ; bp->name ; bp++) {
if (*bp->name == *name && equal(bp->name, name))
return bp->code;
}
return -1;
}
/*
* 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;
}
}
}
/*
* 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 index;
int firstchange;
int bltin;
old = pathval();
new = newval;
firstchange = 9999; /* assume no change */
index = 0;
bltin = -1;
for (;;) {
if (*old != *new) {
firstchange = index;
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 = index;
if (*new == ':') {
index++;
}
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.
*/
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
INCLUDE "exec.h"
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.
*/
STATIC struct tblentry **lastcmdentry;
STATIC struct tblentry *
cmdlookup(char *name, int add)
{
int hashval;
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;
}
/*
* Add a new command entry, replacing any existing command entry for
* the same name.
*/
static void
addcmdentry(char *name, struct cmdentry *entry)
{
struct tblentry *cmdp;
INTOFF;
cmdp = cmdlookup(name, 1);
if (cmdp->cmdtype == CMDFUNCTION) {
freefunc(cmdp->param.func);
}
cmdp->cmdtype = entry->cmdtype;
cmdp->param = entry->u;
INTON;
}
/*
* Define a shell function.
*/
void
defun(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.
*/
int
unsetfunc(char *name)
{
struct tblentry *cmdp;
if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) {
freefunc(cmdp->param.func);
delete_cmd_entry();
return (0);
}
return (0);
}
/*
* Locate and print what a word is...
*/
int
typecmd(int argc, char **argv)
{
struct cmdentry entry;
struct tblentry *cmdp;
char **pp;
struct alias *ap;
int i;
int error = 0;
extern char *const parsekwd[];
for (i = 1; i < argc; i++) {
out1str(argv[i]);
/* First look at the keywords */
for (pp = (char **)parsekwd; *pp; pp++)
if (**pp == *argv[i] && equal(*pp, argv[i]))
break;
if (*pp) {
out1str(" is a shell keyword\n");
continue;
}
/* Then look at the aliases */
if ((ap = lookupalias(argv[i], 1)) != NULL) {
out1fmt(" is an alias for %s\n", 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;
}
else {
/* Finally use brute force */
find_command(argv[i], &entry, 0, pathval());
}
switch (entry.cmdtype) {
case CMDNORMAL: {
if (strchr(argv[i], '/') == NULL) {
char *path = pathval(), *name;
int j = entry.u.index;
do {
name = padvance(&path, argv[i]);
stunalloc(name);
} while (--j >= 0);
out1fmt(" is%s %s\n",
cmdp ? " a tracked alias for" : "", name);
} else {
if (access(argv[i], X_OK) == 0)
out1fmt(" is %s\n", argv[i]);
else
out1fmt(": %s\n", strerror(errno));
}
break;
}
case CMDFUNCTION:
out1str(" is a shell function\n");
break;
case CMDBUILTIN:
out1str(" is a shell builtin\n");
break;
default:
out1str(": not found\n");
error |= 127;
break;
}
}
return error;
}
/*
* $PchId: exec.c,v 1.6 2006/04/10 14:47:03 philip Exp $
*/