/* vi: set sw=8 ts=8: */
/*
* hush.c -- a prototype Bourne shell grammar parser
* Intended to follow the original Thompson and Ritchie
* "small and simple is beautiful" philosophy, which
* incidentally is a good match to today's BusyBox.
*
* Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
*
* Credits:
* The parser routines proper are all original material, first
* written Dec 2000 and Jan 2001 by Larry Doolittle.
* The execution engine, the builtins, and much of the underlying
* support has been adapted from busybox-0.49pre's lash,
* which is Copyright (C) 2000 by Lineo, Inc., and
* written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
* That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
* Erik W. Troan, which they placed in the public domain. I don't know
* how much of the Johnson/Troan code has survived the repeated rewrites.
* Other credits:
* simple_itoa() was lifted from boa-0.93.15
* b_addchr() derived from similar w_addchar function in glibc-2.2
* setup_redirect(), redirect_opt_num(), and big chunks of main()
* and many builtins derived from contributions by Erik Andersen
* miscellaneous bugfixes from Matt Kraai
*/
/** @page shell_notes Simple Shell Environment: Hush
*
* @par Notes from the source:
*
* Intended to follow the original Thompson and Ritchie "small and simple
* is beautiful" philosophy, which incidentally is a good match to
* today's BusyBox.
*
* There are two big (and related) architecture differences between
* this parser and the lash parser. One is that this version is
* actually designed from the ground up to understand nearly all
* of the Bourne grammar. The second, consequential change is that
* the parser and input reader have been turned inside out. Now,
* the parser is in control, and asks for input as needed. The old
* way had the input reader in control, and it asked for parsing to
* take place as needed. The new way makes it much easier to properly
* handle the recursion implicit in the various substitutions, especially
* across continuation lines.
*
* Bash grammar not implemented: (how many of these were in original sh?)
* - $@ (those sure look like weird quoting rules)
* - $_
* - ! negation operator for pipes
* - &> and >& redirection of stdout+stderr
* - Brace Expansion
* - Tilde Expansion
* - fancy forms of Parameter Expansion
* - aliases
* - Arithmetic Expansion
* - <(list) and >(list) Process Substitution
* - reserved words: case, esac, select, function
* - Here Documents ( << word )
* - Functions
*
* Major bugs:
* - job handling woefully incomplete and buggy
* - reserved word execution woefully incomplete and buggy
*
* to-do:
* - port selected bugfixes from post-0.49 busybox lash - done?
* - finish implementing reserved words: for, while, until, do, done
* - change { and } from special chars to reserved words
* - builtins: break, continue, eval, return, set, trap, ulimit
* - test magic exec
* - handle children going into background
* - clean up recognition of null pipes
* - check setting of global_argc and global_argv
* - control-C handling, probably with longjmp
* - follow IFS rules more precisely, including update semantics
* - figure out what to do with backslash-newline
* - explain why we use signal instead of sigaction
* - propagate syntax errors, die on resource errors?
* - continuation lines, both explicit and implicit - done?
* - memory leak finding and plugging - done?
* - more testing, especially quoting rules and redirection
* - document how quoting rules not precisely followed for variable assignments
* - maybe change map[] to use 2-bit entries
* - (eventually) remove all the printf's
*
* Things that do _not_ work in this environment:
*
* - redirecting (stdout to a file for example)
* - recursion
*
* Enable the "Hush parser" in "General Settings", "Select your shell" to
* get the new console feeling.
*
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <malloc.h> /* malloc, free, realloc*/
#include <xfuncs.h>
#include <linux/ctype.h> /* isalpha, isdigit */
#include <common.h> /* readline */
#include <environment.h>
#include <command.h> /* find_cmd */
#include <driver.h>
#include <errno.h>
#include <fs.h>
#include <libbb.h>
#include <glob.h>
/*cmd_boot.c*/
extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]); /* do_bootd */
#define SPECIAL_VAR_SYMBOL 03
#define EXIT_SUCCESS 0
#define EOF -1
#define syntax() syntax_err()
#define xstrdup strdup
#define error_msg printf
typedef enum {
PIPE_SEQ = 1,
PIPE_AND = 2,
PIPE_OR = 3,
PIPE_BG = 4,
} pipe_style;
/* might eventually control execution */
typedef enum {
RES_NONE = 0,
RES_IF = 1,
RES_THEN = 2,
RES_ELIF = 3,
RES_ELSE = 4,
RES_FI = 5,
RES_FOR = 6,
RES_WHILE = 7,
RES_UNTIL = 8,
RES_DO = 9,
RES_DONE = 10,
RES_XXXX = 11,
RES_IN = 12,
RES_SNTX = 13
} reserved_style;
#define FLAG_END (1<<RES_NONE)
#define FLAG_IF (1<<RES_IF)
#define FLAG_THEN (1<<RES_THEN)
#define FLAG_ELIF (1<<RES_ELIF)
#define FLAG_ELSE (1<<RES_ELSE)
#define FLAG_FI (1<<RES_FI)
#define FLAG_FOR (1<<RES_FOR)
#define FLAG_WHILE (1<<RES_WHILE)
#define FLAG_UNTIL (1<<RES_UNTIL)
#define FLAG_DO (1<<RES_DO)
#define FLAG_DONE (1<<RES_DONE)
#define FLAG_IN (1<<RES_IN)
#define FLAG_START (1<<RES_XXXX)
#define FLAG_EXIT_FROM_LOOP 1
#define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
#define FLAG_REPARSING (1 << 2) /* >=2nd pass */
/* This holds pointers to the various results of parsing */
struct p_context {
struct child_prog *child;
struct pipe *list_head;
struct pipe *pipe;
reserved_style w;
int old_flag; /* for figuring out valid reserved words */
struct p_context *stack;
int type; /* define type of parser : ";$" common or special symbol */
/* How about quoting status? */
char **global_argv;
unsigned int global_argc;
};
struct child_prog {
char **argv; /* program name and arguments */
int argc; /* number of program arguments */
struct pipe *group; /* if non-NULL, first in group or subshell */
int sp; /* number of SPECIAL_VAR_SYMBOL */
int type;
glob_t glob_result; /* result of parameter globbing */
};
struct pipe {
int num_progs; /* total number of programs in job */
struct child_prog *progs; /* array of commands in pipe */
struct pipe *next; /* to track background commands */
pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
reserved_style r_mode; /* supports if, for, while, until */
};
static char console_buffer[CONFIG_CBSIZE]; /* console I/O buffer */
/* globals, connect us to the outside world
* the first three support $?, $#, and $1 */
static unsigned int last_return_code;
/* "globals" within this file */
static uchar *ifs;
static char map[256];
#define B_CHUNK (100)
#define B_NOSPAC 1
typedef struct {
char *data;
int length;
int maxlen;
int quote;
int nonnull;
} o_string;
#define NULL_O_STRING {NULL,0,0,0,0}
/* used for initialization:
o_string foo = NULL_O_STRING; */
/* I can almost use ordinary FILE *. Is open_memstream() universally
* available? Where is it documented? */
struct in_str {
const char *p;
int __promptme;
int promptmode;
int (*get) (struct in_str *);
int (*peek) (struct in_str *);
};
#define b_getch(input) ((input)->get(input))
#define b_peek(input) ((input)->peek(input))
#define final_printf debug
static void syntax_err(void) {
printf("syntax error\n");
}
/* o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
static void b_reset(o_string *o);
static int b_addqchr(o_string *o, int ch, int quote);
/* in_str manipulations: */
static int static_get(struct in_str *i);
static int static_peek(struct in_str *i);
static int file_get(struct in_str *i);
static int file_peek(struct in_str *i);
static void setup_file_in_str(struct in_str *i);
static void setup_string_in_str(struct in_str *i, const char *s);
/* "run" the final data structures: */
static int free_pipe_list(struct pipe *head, int indent);
static int free_pipe(struct pipe *pi, int indent);
/* really run the final data structures: */
static int run_list_real(struct pipe *pi);
static int run_pipe_real(struct pipe *pi);
/* extended glob support: */
/* variable assignment: */
static int is_assignment(const char *s);
/* data structure manipulation: */
static void initialize_context(struct p_context *ctx);
static int done_word(o_string *dest, struct p_context *ctx);
static int done_command(struct p_context *ctx);
static int done_pipe(struct p_context *ctx, pipe_style type);
/* primary string parsing: */
static const char *lookup_param(char *src);
static char *make_string(char **inp);
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
/* setup: */
static int parse_stream_outer(struct p_context *ctx, struct in_str *inp, int flag);
static int parse_string_outer(struct p_context *ctx, const char *s, int flag);
/* local variable support */
static char **make_list_in(char **inp, char *name);
static char *insert_var_value(char *inp);
static int set_local_var(const char *s, int flg_export);
static int execute_script(const char *path, int argc, char *argv[]);
static int source_script(const char *path, int argc, char *argv[]);
static int b_check_space(o_string *o, int len)
{
/* It would be easy to drop a more restrictive policy
* in here, such as setting a maximum string length */
if (o->length + len > o->maxlen) {
char *old_data = o->data;
/* assert (data == NULL || o->maxlen != 0); */
o->maxlen += max(2*len, B_CHUNK);
o->data = realloc(o->data, 1 + o->maxlen);
if (o->data == NULL) {
free(old_data);
}
}
return o->data == NULL;
}
static int b_addchr(o_string *o, int ch)
{
debug("b_addchr: %c %d %p\n", ch, o->length, o);
if (b_check_space(o, 1))
return B_NOSPAC;
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
return 0;
}
static void b_reset(o_string *o)
{
o->length = 0;
o->nonnull = 0;
if (o->data != NULL) *o->data = '\0';
}
static void b_free(o_string *o)
{
b_reset(o);
free(o->data);
o->data = NULL;
o->maxlen = 0;
}
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static int b_addqchr(o_string *o, int ch, int quote)
{
if (quote && strchr("*?[",ch)) {
int rc;
rc = b_addchr(o, '\\');
if (rc)
return rc;
}
return b_addchr(o, ch);
}
/* belongs in utility.c */
char *simple_itoa(unsigned int i)
{
/* 21 digits plus null terminator, good for 64-bit or smaller ints */
static char local[22];
char *p = &local[21];
*p-- = '\0';
do {
*p-- = '0' + i % 10;
i /= 10;
} while (i > 0);
return p + 1;
}
static int b_adduint(o_string *o, unsigned int i)
{
int r;
char *p = simple_itoa(i);
/* no escape checking necessary */
do {
r=b_addchr(o, *p++);
} while (r==0 && *p);
return r;
}
static int static_get(struct in_str *i)
{
int ch=*i->p++;
if (ch=='\0')
return EOF;
return ch;
}
static int static_peek(struct in_str *i)
{
return *i->p;
}
static char *getprompt(void)
{
static char *prompt;
if (!prompt)
prompt = xmalloc(PATH_MAX + strlen(CONFIG_PROMPT) + 1);
sprintf(prompt, "%s%s ", CONFIG_PROMPT, getcwd());
return prompt;
}
static void get_user_input(struct in_str *i)
{
int n;
static char the_command[CONFIG_CBSIZE];
i->__promptme = 1;
if (i->promptmode == 1) {
n = readline(getprompt(), console_buffer, CONFIG_CBSIZE);
} else {
n = readline(CONFIG_PROMPT_HUSH_PS2, console_buffer, CONFIG_CBSIZE);
}
if (n == -1 ) {
i->__promptme = 0;
n = 0;
}
console_buffer[n] = '\n';
console_buffer[n+1]= '\0';
if (i->promptmode == 1) {
strcpy(the_command,console_buffer);
i->p = the_command;
} else {
if (console_buffer[0] != '\n') {
if (strlen(the_command) + strlen(console_buffer)
< CONFIG_CBSIZE) {
n = strlen(the_command);
the_command[n-1] = ' ';
strcpy(&the_command[n],console_buffer);
}
else {
the_command[0] = '\n';
the_command[1] = '\0';
}
}
if (i->__promptme == 0) {
the_command[0] = '\n';
the_command[1] = '\0';
}
i->p = console_buffer;
}
}
/* This is the magic location that prints prompts
* and gets data back from the user */
static int file_get(struct in_str *i)
{
int ch;
ch = 0;
/* If there is data waiting, eat it up */
if (i->p && *i->p) {
ch=*i->p++;
} else {
/* need to double check i->file because we might be doing something
* more complicated by now, like sourcing or substituting. */
while(! i->p || strlen(i->p)==0 ) {
get_user_input(i);
}
i->promptmode=2;
if (i->p && *i->p) {
ch=*i->p++;
}
debug("b_getch: got a %d\n", ch);
}
return ch;
}
/* All the callers guarantee this routine will never be
* used right after a newline, so prompting is not needed.
*/
static int file_peek(struct in_str *i)
{
return *i->p;
}
static void setup_file_in_str(struct in_str *i)
{
i->peek = file_peek;
i->get = file_get;
i->__promptme=1;
i->promptmode=1;
i->p = NULL;
}
static void setup_string_in_str(struct in_str *i, const char *s)
{
i->peek = static_peek;
i->get = static_get;
i->__promptme=1;
i->promptmode=1;
i->p = s;
}
/* run_pipe_real() starts all the jobs, but doesn't wait for anything
* to finish. See checkjobs().
*
* return code is normally -1, when the caller has to wait for children
* to finish to determine the exit status of the pipe. If the pipe
* is a simple builtin command, however, the action is done by the
* time run_pipe_real returns, and the exit code is provided as the
* return value.
*
* The input of the pipe is always stdin, the output is always
* stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
* because it tries to avoid running the command substitution in
* subshell, when that is in fact necessary. The subshell process
* now has its stdout directed to the input of the appropriate pipe,
* so this routine is noticeably simpler.
*/
static int run_pipe_real(struct pipe *pi)
{
int i;
int nextin;
struct child_prog *child;
char *p;
char *path;
int ret;
# if __GNUC__
/* Avoid longjmp clobbering */
(void) &i;
(void) &nextin;
(void) &child;
# endif
nextin = 0;
/* Check if this is a simple builtin (not part of a pipe).
* Builtins within pipes have to fork anyway, and are handled in
* pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
*/
if (pi->num_progs == 1)
child = & (pi->progs[0]);
if (pi->num_progs == 1 && child->group) {
int rcode;
debug("non-subshell grouping\n");
rcode = run_list_real(child->group);
return rcode;
} else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
if (i!=0 && child->argv[i]==NULL) {
/* assignments, but no command: set the local environment */
for (i=0; child->argv[i]!=NULL; i++) {
/* Ok, this case is tricky. We have to decide if this is a
* local variable, or an already exported variable. If it is
* already exported, we have to export the new value. If it is
* not exported, we need only set this as a local variable.
* This junk is all to decide whether or not to export this
* variable. */
int export_me=0;
char *name, *value;
name = xstrdup(child->argv[i]);
debug("Local environment set: %s\n", name);
value = strchr(name, '=');
if (value)
*value=0;
free(name);
p = insert_var_value(child->argv[i]);
set_local_var(p, export_me);
if (p != child->argv[i])
free(p);
}
return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
}
for (i = 0; is_assignment(child->argv[i]); i++) {
p = insert_var_value(child->argv[i]);
set_local_var(p, 0);
if (p != child->argv[i]) {
child->sp--;
free(p);
}
}
if (child->sp) {
char * str = NULL;
struct p_context ctx;
str = make_string((child->argv + i));
parse_string_outer(&ctx, str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
free(str);
return last_return_code;
}
if (strchr(child->argv[i], '/')) {
return execute_script(child->argv[i], child->argc-i, &child->argv[i]);
}
if ((path = find_execable(child->argv[i]))) {
ret = execute_script(path, child->argc-i, &child->argv[i]);
free(path);
return ret;
}
return execute_command(child->argc - i, &child->argv[i]);
}
return -1;
}
static int run_list_real(struct pipe *pi)
{
char *save_name = NULL;
char **list = NULL;
char **save_list = NULL;
struct pipe *rpipe;
int flag_rep = 0;
int rcode=0, flag_skip=1;
int flag_restore = 0;
int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
/* check syntax for "for" */
for (rpipe = pi; rpipe; rpipe = rpipe->next) {
if ((rpipe->r_mode == RES_IN ||
rpipe->r_mode == RES_FOR) &&
(rpipe->next == NULL)) {
syntax();
return 1;
}
if ((rpipe->r_mode == RES_IN &&
(rpipe->next->r_mode == RES_IN &&
rpipe->next->progs->argv != NULL))||
(rpipe->r_mode == RES_FOR &&
rpipe->next->r_mode != RES_IN)) {
syntax();
return 1;
}
}
for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
pi->r_mode == RES_FOR) {
/* check Ctrl-C */
if (ctrlc())
return 1;
flag_restore = 0;
if (!rpipe) {
flag_rep = 0;
rpipe = pi;
}
}
rmode = pi->r_mode;
debug("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
if (rmode == skip_more_in_this_rmode && flag_skip) {
if (pi->followup == PIPE_SEQ) flag_skip=0;
continue;
}
flag_skip = 1;
skip_more_in_this_rmode = RES_XXXX;
if (rmode == RES_THEN || rmode == RES_ELSE)
if_code = next_if_code;
if (rmode == RES_THEN && if_code)
continue;
if (rmode == RES_ELSE && !if_code)
continue;
if (rmode == RES_ELIF && !if_code)
break;
if (rmode == RES_FOR && pi->num_progs) {
if (!list) {
/* if no variable values after "in" we skip "for" */
if (!pi->next->progs->argv)
continue;
/* create list of variable values */
list = make_list_in(pi->next->progs->argv,
pi->progs->argv[0]);
save_list = list;
save_name = pi->progs->argv[0];
pi->progs->argv[0] = NULL;
flag_rep = 1;
}
if (!(*list)) {
free(pi->progs->argv[0]);
free(save_list);
list = NULL;
flag_rep = 0;
pi->progs->argv[0] = save_name;
continue;
} else {
/* insert new value from list for variable */
if (pi->progs->argv[0])
free(pi->progs->argv[0]);
pi->progs->argv[0] = *list++;
}
}
if (rmode == RES_IN)
continue;
if (rmode == RES_DO) {
if (!flag_rep)
continue;
}
if ((rmode == RES_DONE)) {
if (flag_rep) {
flag_restore = 1;
} else {
rpipe = NULL;
}
}
if (pi->num_progs == 0)
continue;
rcode = run_pipe_real(pi);
debug("run_pipe_real returned %d\n",rcode);
if (rcode < -1) {
last_return_code = -rcode - 2;
return -2; /* exit */
}
last_return_code=rcode;
if ( rmode == RES_IF || rmode == RES_ELIF )
next_if_code=rcode; /* can be overwritten a number of times */
if (rmode == RES_WHILE)
flag_rep = !last_return_code;
if (rmode == RES_UNTIL)
flag_rep = last_return_code;
if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
(rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
skip_more_in_this_rmode=rmode;
}
return rcode;
}
#ifdef DEBUG
/* broken, of course, but OK for testing */
static char *indenter(int i)
{
static char blanks[]=" ";
return &blanks[sizeof(blanks)-i-1];
}
#endif
/* return code is the exit status of the pipe */
static int free_pipe(struct pipe *pi, int indent)
{
char **p;
struct child_prog *child;
int a, i, ret_code=0;
for (i=0; i<pi->num_progs; i++) {
child = &pi->progs[i];
final_printf("%s command %d:\n",indenter(indent),i);
if (child->argv) {
for (a=0,p=child->argv; *p; a++,p++) {
final_printf("%s argv[%d] = %s\n",indenter(indent),a,*p);
}
globfree(&child->glob_result);
child->argv=NULL;
} else if (child->group) {
ret_code = free_pipe_list(child->group,indent+3);
final_printf("%s end group\n",indenter(indent));
} else {
final_printf("%s (nil)\n",indenter(indent));
}
}
free(pi->progs); /* children are an array, they get freed all at once */
pi->progs=NULL;
return ret_code;
}
static int free_pipe_list(struct pipe *head, int indent)
{
int rcode=0; /* if list has no members */
struct pipe *pi, *next;
for (pi=head; pi; pi=next) {
final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
rcode = free_pipe(pi, indent);
final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
next=pi->next;
pi->next=NULL;
free(pi);
}
return rcode;
}
/* The API for glob is arguably broken. This routine pushes a non-matching
* string into the output structure, removing non-backslashed backslashes.
* If someone can prove me wrong, by performing this function within the
* original glob(3) api, feel free to rewrite this routine into oblivion.
* Return code (0 vs. GLOB_NOSPACE) matches glob(3).
* XXX broken if the last character is '\\', check that before calling.
*/
static int globhack(const char *src, int flags, glob_t *pglob)
{
int cnt=0, pathc;
const char *s;
char *dest;
for (cnt=1, s=src; s && *s; s++) {
if (*s == '\\') s++;
cnt++;
}
dest = xmalloc(cnt);
if (!(flags & GLOB_APPEND)) {
pglob->gl_pathv = NULL;
pglob->gl_pathc = 0;
pglob->gl_offs = 0;
}
pathc = ++pglob->gl_pathc;
pglob->gl_pathv = xrealloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
pglob->gl_pathv[pathc-1] = dest;
pglob->gl_pathv[pathc] = NULL;
for (s=src; s && *s; s++, dest++) {
if (*s == '\\') s++;
*dest = *s;
}
*dest='\0';
return 0;
}
/* XXX broken if the last character is '\\', check that before calling */
static int glob_needed(const char *s)
{
#ifdef CONFIG_GLOB
for (; *s; s++) {
if (*s == '\\') s++;
if (strchr("*[?",*s))
return 1;
}
#endif
return 0;
}
static int xglob(o_string *dest, int flags, glob_t *pglob)
{
int gr;
/* short-circuit for null word */
/* we can code this better when the debug's are gone */
if (dest->length == 0) {
if (dest->nonnull) {
/* bash man page calls this an "explicit" null */
gr = globhack(dest->data, flags, pglob);
debug("globhack returned %d\n",gr);
} else {
return 0;
}
} else if (glob_needed(dest->data)) {
gr = glob(dest->data, flags, NULL, pglob);
debug("glob returned %d\n",gr);
if (gr == GLOB_NOMATCH) {
/* quote removal, or more accurately, backslash removal */
gr = globhack(dest->data, flags, pglob);
debug("globhack returned %d\n",gr);
}
} else {
gr = globhack(dest->data, flags, pglob);
debug("globhack returned %d\n",gr);
}
if (gr != 0) { /* GLOB_ABORTED ? */
error_msg("glob(3) error %d",gr);
}
/* globprint(glob_target); */
return gr;
}
/* Select which version we will use */
static int run_list(struct pipe *pi)
{
int rcode = 0;
rcode = run_list_real(pi);
/* free_pipe_list has the side effect of clearing memory
* In the long run that function can be merged with run_list_real,
* but doing that now would hobble the debugging effort. */
free_pipe_list(pi,0);
return rcode;
}
static char *get_dollar_var(char ch);
/* This is used to set local shell variables
flg_export==0 if only local (not exporting) variable
flg_export==1 if "new" exporting environ
flg_export>1 if current startup environ (not call putenv()) */
static int set_local_var(const char *s, int flg_export)
{
char *name, *value;
int ret;
/* might be possible! */
if (!isalpha(*s))
return -1;
name = strdup(s);
/* Assume when we enter this function that we are already in
* NAME=VALUE format. So the first order of business is to
* split 's' on the '=' into 'name' and 'value' */
value = strchr(name, '=');
if (value==0 && ++value==0) {
free(name);
return -1;
}
*value++ = 0;
ret = setenv(name, value);
free(name);
return ret;
}
static int is_assignment(const char *s)
{
if (s == NULL)
return 0;
if (!isalpha(*s))
return 0;
++s;
while(isalnum(*s) || *s=='_' || *s=='.')
++s;
return *s=='=';
}
static struct pipe *new_pipe(void) {
return (struct pipe *)xzalloc(sizeof(struct pipe));
}
static void initialize_context(struct p_context *ctx)
{
ctx->pipe=NULL;
ctx->child=NULL;
ctx->list_head=new_pipe();
ctx->pipe=ctx->list_head;
ctx->w=RES_NONE;
ctx->stack=NULL;
ctx->old_flag=0;
done_command(ctx); /* creates the memory for working child */
}
/* normal return is 0
* if a reserved word is found, and processed, return 1
* should handle if, then, elif, else, fi, for, while, until, do, done.
* case, function, and select are obnoxious, save those for later.
*/
struct reserved_combo {
char *literal;
int code;
long flag;
};
/* Mostly a list of accepted follow-up reserved words.
* FLAG_END means we are done with the sequence, and are ready
* to turn the compound list into a command.
* FLAG_START means the word must start a new compound list.
*/
static struct reserved_combo reserved_list[] = {
{ "if", RES_IF, FLAG_THEN | FLAG_START },
{ "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
{ "elif", RES_ELIF, FLAG_THEN },
{ "else", RES_ELSE, FLAG_FI },
{ "fi", RES_FI, FLAG_END },
{ "for", RES_FOR, FLAG_IN | FLAG_START },
{ "while", RES_WHILE, FLAG_DO | FLAG_START },
{ "until", RES_UNTIL, FLAG_DO | FLAG_START },
{ "in", RES_IN, FLAG_DO },
{ "do", RES_DO, FLAG_DONE },
{ "done", RES_DONE, FLAG_END }
};
#define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
static int reserved_word(o_string *dest, struct p_context *ctx)
{
struct reserved_combo *r;
for (r=reserved_list;
r<reserved_list+NRES; r++) {
if (strcmp(dest->data, r->literal) == 0) {
debug("found reserved word %s, code %d\n",r->literal,r->code);
if (r->flag & FLAG_START) {
struct p_context *new = xmalloc(sizeof(struct p_context));
debug("push stack\n");
if (ctx->w == RES_IN || ctx->w == RES_FOR) {
syntax();
free(new);
ctx->w = RES_SNTX;
b_reset(dest);
return 1;
}
*new = *ctx; /* physical copy */
initialize_context(ctx);
ctx->stack=new;
} else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
syntax();
ctx->w = RES_SNTX;
b_reset(dest);
return 1;
}
ctx->w=r->code;
ctx->old_flag = r->flag;
if (ctx->old_flag & FLAG_END) {
struct p_context *old;
debug("pop stack\n");
done_pipe(ctx,PIPE_SEQ);
old = ctx->stack;
old->child->group = ctx->list_head;
*ctx = *old; /* physical copy */
free(old);
}
b_reset (dest);
return 1;
}
}
return 0;
}
/* normal return is 0.
* Syntax or xglob errors return 1. */
static int done_word(o_string *dest, struct p_context *ctx)
{
struct child_prog *child=ctx->child;
glob_t *glob_target;
int gr, flags = 0;
debug("done_word: %s %p\n", dest->data, child);
if (dest->length == 0 && !dest->nonnull) {
debug(" true null, ignored\n");
return 0;
}
if (child->group) {
syntax();
return 1; /* syntax error, groups and arglists don't mix */
}
if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
debug("checking %s for reserved-ness\n",dest->data);
if (reserved_word(dest,ctx))
return ctx->w==RES_SNTX;
}
glob_target = &child->glob_result;
if (child->argv)
flags |= GLOB_APPEND;
gr = xglob(dest, flags, glob_target);
if (gr)
return 1;
b_reset(dest);
child->argv = glob_target->gl_pathv;
child->argc = glob_target->gl_pathc;
if (ctx->w == RES_FOR) {
done_word(dest,ctx);
done_pipe(ctx,PIPE_SEQ);
}
return 0;
}
/* The only possible error here is out of memory, in which case
* xmalloc exits. */
static int done_command(struct p_context *ctx)
{
/* The child is really already in the pipe structure, so
* advance the pipe counter and make a new, null child.
* Only real trickiness here is that the uncommitted
* child structure, to which ctx->child points, is not
* counted in pi->num_progs. */
struct pipe *pi=ctx->pipe;
struct child_prog *prog=ctx->child;
if (prog && prog->group == NULL
&& prog->argv == NULL
) {
debug("done_command: skipping null command\n");
return 0;
} else if (prog) {
pi->num_progs++;
debug("done_command: num_progs incremented to %d\n",pi->num_progs);
} else {
debug("done_command: initializing\n");
}
pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
prog = pi->progs + pi->num_progs;
prog->glob_result.gl_pathv = NULL;
prog->argv = NULL;
prog->group = NULL;
prog->sp = 0;
ctx->child = prog;
prog->type = ctx->type;
/* but ctx->pipe and ctx->list_head remain unchanged */
return 0;
}
static int done_pipe(struct p_context *ctx, pipe_style type)
{
struct pipe *new_p;
done_command(ctx); /* implicit closure of previous command */
debug("done_pipe, type %d\n", type);
ctx->pipe->followup = type;
ctx->pipe->r_mode = ctx->w;
new_p=new_pipe();
ctx->pipe->next = new_p;
ctx->pipe = new_p;
ctx->child = NULL;
done_command(ctx); /* set up new pipe to accept commands */
return 0;
}
/* basically useful version until someone wants to get fancier,
* see the bash man page under "Parameter Expansion" */
static const char *lookup_param(char *src)
{
if (!src)
return NULL;
if (*src == '$')
return get_dollar_var(src[1]);
return getenv(src);
}
static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
{
struct in_str foo;
setup_string_in_str(&foo, src);
return parse_stream(dest, ctx, &foo, '\0');
}
static char *get_dollar_var(char ch)
{
static char buf[40];
buf[0] = '\0';
switch (ch) {
case '?':
sprintf(buf, "%u", (unsigned int)last_return_code);
break;
default:
return NULL;
}
return buf;
}
/* return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
{
int advance = 0, i;
int ch = input->peek(input); /* first character after the $ */
debug("handle_dollar: ch=%c\n",ch);
if (isalpha(ch)) {
b_addchr(dest, SPECIAL_VAR_SYMBOL);
ctx->child->sp++;
while(ch=b_peek(input),isalnum(ch) || ch=='_' || ch=='.') {
b_getch(input);
b_addchr(dest,ch);
}
b_addchr(dest, SPECIAL_VAR_SYMBOL);
} else if (isdigit(ch)) {
i = ch - '0'; /* XXX is $0 special? */
if (i < ctx->global_argc) {
parse_string(dest, ctx, ctx->global_argv[i]); /* recursion */
}
advance = 1;
} else {
switch (ch) {
case '?':
ctx->child->sp++;
b_addchr(dest, SPECIAL_VAR_SYMBOL);
b_addchr(dest, '$');
b_addchr(dest, '?');
b_addchr(dest, SPECIAL_VAR_SYMBOL);
advance = 1;
break;
case '#':
b_adduint(dest,ctx->global_argc ? ctx->global_argc-1 : 0);
advance = 1;
break;
case '{':
b_addchr(dest, SPECIAL_VAR_SYMBOL);
ctx->child->sp++;
b_getch(input);
/* XXX maybe someone will try to escape the '}' */
while(ch=b_getch(input),ch!=EOF && ch!='}') {
b_addchr(dest,ch);
}
if (ch != '}') {
syntax();
return 1;
}
b_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
default:
b_addqchr(dest,'$',dest->quote);
}
}
/* Eat the character if the flag was set. If the compiler
* is smart enough, we could substitute "b_getch(input);"
* for all the "advance = 1;" above, and also end up with
* a nice size-optimized program. Hah! That'll be the day.
*/
if (advance)
b_getch(input);
return 0;
}
/* return code is 0 for normal exit, 1 for syntax error */
static int parse_stream(o_string *dest, struct p_context *ctx,
struct in_str *input, int end_trigger)
{
unsigned int ch, m;
int next;
/* Only double-quote state is handled in the state variable dest->quote.
* A single-quote triggers a bypass of the main loop until its mate is
* found. When recursing, quote state is passed in via dest->quote. */
debug("parse_stream, end_trigger=%d\n",end_trigger);
while ((ch=b_getch(input))!=EOF) {
m = map[ch];
if (input->__promptme == 0)
return 1;
next = (ch == '\n') ? 0 : b_peek(input);
debug("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
ch >= ' ' ? ch : '.', ch, m,
dest->quote, ctx->stack == NULL ? '*' : '.');
if (m==0 || ((m==1 || m==2) && dest->quote)) {
b_addqchr(dest, ch, dest->quote);
} else {
if (m==2) { /* unquoted IFS */
if (done_word(dest, ctx)) {
return 1;
}
/* If we aren't performing a substitution, treat a newline as a
* command separator. */
if (end_trigger != '\0' && ch=='\n')
done_pipe(ctx,PIPE_SEQ);
}
if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
debug("leaving parse_stream (triggered)\n");
return 0;
}
if (m!=2) {
switch (ch) {
case '#':
if (dest->length == 0 && !dest->quote) {
while(ch=b_peek(input),ch!=EOF && ch!='\n') {
b_getch(input);
}
} else {
b_addqchr(dest, ch, dest->quote);
}
break;
case '\\':
if (next == EOF) {
syntax();
return 1;
}
b_addqchr(dest, '\\', dest->quote);
b_addqchr(dest, b_getch(input), dest->quote);
break;
case '$':
if (handle_dollar(dest, ctx, input)!=0)
return 1;
break;
case '\'':
dest->nonnull = 1;
while(ch=b_getch(input),ch!=EOF && ch!='\'') {
if(input->__promptme == 0)
return 1;
b_addchr(dest,ch);
}
if (ch==EOF) {
syntax();
return 1;
}
break;
case '"':
dest->nonnull = 1;
dest->quote = !dest->quote;
break;
case ';':
done_word(dest, ctx);
done_pipe(ctx,PIPE_SEQ);
break;
case '&':
done_word(dest, ctx);
if (next=='&') {
b_getch(input);
done_pipe(ctx,PIPE_AND);
} else {
syntax_err();
return 1;
}
break;
case '|':
done_word(dest, ctx);
if (next=='|') {
b_getch(input);
done_pipe(ctx,PIPE_OR);
} else {
/* we could pick up a file descriptor choice here
* with redirect_opt_num(), but bash doesn't do it.
* "echo foo 2| cat" yields "foo 2". */
syntax_err();
return 1;
}
break;
default:
syntax(); /* this is really an internal logic error */
return 1;
}
}
}
}
/* complain if quote? No, maybe we just finished a command substitution
* that was quoted. Example:
* $ echo "`cat foo` plus more"
* and we just got the EOF generated by the subshell that ran "cat foo"
* The only real complaint is if we got an EOF when end_trigger != '\0',
* that is, we were really supposed to get end_trigger, and never got
* one before the EOF. Can't use the standard "syntax error" return code,
* so that parse_stream_outer can distinguish the EOF and exit smoothly. */
debug("leaving parse_stream (EOF)\n");
if (end_trigger != '\0') return -1;
return 0;
}
static void mapset(const unsigned char *set, int code)
{
const unsigned char *s;
for (s=set; *s; s++) map[*s] = code;
}
static void update_ifs_map(void)
{
/* char *ifs and char map[256] are both globals. */
ifs = (uchar *)getenv("IFS");
ifs = NULL;
if (ifs == NULL) ifs=(uchar *)" \t\n";
/* Precompute a list of 'flow through' behavior so it can be treated
* quickly up front. Computation is necessary because of IFS.
* Special case handling of IFS == " \t\n" is not implemented.
* The map[] array only really needs two bits each, and on most machines
* that would be faster because of the reduced L1 cache footprint.
*/
memset(map,0,sizeof(map)); /* most characters flow through always */
mapset((uchar *)"\\$'\"", 3); /* never flow through */
mapset((uchar *)";&|#", 1); /* flow through if quoted */
mapset(ifs, 2); /* also flow through if quoted */
}
/* most recursion does not come through here, the exeception is
* from builtin_source() */
static int parse_stream_outer(struct p_context *ctx, struct in_str *inp, int flag)
{
o_string temp=NULL_O_STRING;
int rcode;
int code = 0;
do {
ctx->type = flag;
initialize_context(ctx);
update_ifs_map();
if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING))
mapset((uchar *)";$&|", 0);
inp->promptmode=1;
rcode = parse_stream(&temp, ctx, inp, '\n');
if (rcode != 1 && ctx->old_flag != 0) {
syntax();
}
if (rcode != 1 && ctx->old_flag == 0) {
done_word(&temp, ctx);
done_pipe(ctx,PIPE_SEQ);
if (ctx->list_head->num_progs) {
code = run_list(ctx->list_head);
} else {
free_pipe_list(ctx->list_head, 0);
continue;
}
if (code == -2) { /* exit */
b_free(&temp);
/* XXX hackish way to not allow exit from main loop */
if (inp->peek == file_peek) {
printf("exit not allowed from main input shell.\n");
code = 0;
continue;
}
code = last_return_code;
break;
}
} else {
if (ctx->old_flag != 0) {
free(ctx->stack);
b_reset(&temp);
}
if (inp->__promptme == 0)
printf("<INTERRUPT>\n");
inp->__promptme = 1;
temp.nonnull = 0;
temp.quote = 0;
inp->p = NULL;
free_pipe_list(ctx->list_head,0);
}
b_free(&temp);
} while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
return (code != 0) ? 1 : 0;
}
static int parse_string_outer(struct p_context *ctx, const char *s, int flag)
{
struct in_str input;
char *p;
const char *cp;
int rcode;
if ( !s || !*s)
return 1;
cp = strchr(s, '\n');
if (!cp || *++cp) {
p = xmalloc(strlen(s) + 2);
strcpy(p, s);
strcat(p, "\n");
setup_string_in_str(&input, p);
rcode = parse_stream_outer(ctx, &input, flag);
free(p);
return rcode;
} else {
setup_string_in_str(&input, s);
return parse_stream_outer(ctx, &input, flag);
}
}
static char *insert_var_value(char *inp)
{
int res_str_len = 0;
int len;
int done = 0;
char *p, *res_str = NULL;
const char *p1;
while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
if (p != inp) {
len = p - inp;
res_str = xrealloc(res_str, (res_str_len + len));
strncpy((res_str + res_str_len), inp, len);
res_str_len += len;
}
inp = ++p;
p = strchr(inp, SPECIAL_VAR_SYMBOL);
*p = '\0';
if ((p1 = lookup_param(inp))) {
len = res_str_len + strlen(p1);
res_str = xrealloc(res_str, (1 + len));
strcpy((res_str + res_str_len), p1);
res_str_len = len;
}
*p = SPECIAL_VAR_SYMBOL;
inp = ++p;
done = 1;
}
if (done) {
res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
strcpy((res_str + res_str_len), inp);
while ((p = strchr(res_str, '\n'))) {
*p = ' ';
}
}
return (res_str == NULL) ? inp : res_str;
}
static char **make_list_in(char **inp, char *name)
{
int len, i;
int name_len = strlen(name);
int n = 0;
char **list;
char *p1, *p2, *p3;
/* create list of variable values */
list = xmalloc(sizeof(*list));
for (i = 0; inp[i]; i++) {
p3 = insert_var_value(inp[i]);
p1 = p3;
while (*p1) {
if ((*p1 == ' ')) {
p1++;
continue;
}
if ((p2 = strchr(p1, ' '))) {
len = p2 - p1;
} else {
len = strlen(p1);
p2 = p1 + len;
}
/* we use n + 2 in realloc for list,because we add
* new element and then we will add NULL element */
list = xrealloc(list, sizeof(*list) * (n + 2));
list[n] = xmalloc(2 + name_len + len);
strcpy(list[n], name);
strcat(list[n], "=");
strncat(list[n], p1, len);
list[n++][name_len + len + 1] = '\0';
p1 = p2;
}
if (p3 != inp[i])
free(p3);
}
list[n] = NULL;
return list;
}
/* Make new string for parser */
static char * make_string(char ** inp)
{
char *p;
char *str = NULL;
int n;
int len = 2;
for (n = 0; inp[n]; n++) {
p = insert_var_value(inp[n]);
str = xrealloc(str, (len + strlen(p)));
if (n) {
strcat(str, " ");
} else {
*str = '\0';
}
strcat(str, p);
len = strlen(str) + 3;
if (p != inp[n])
free(p);
}
len = strlen(str);
*(str + len) = '\n';
*(str + len + 1) = '\0';
return str;
}
int run_command (const char *cmd, int flag)
{
struct p_context ctx;
return parse_string_outer(&ctx, cmd, FLAG_PARSE_SEMICOLON);
}
static int execute_script(const char *path, int argc, char *argv[])
{
int ret;
env_push_context();
ret = source_script(path, argc, argv);
env_pop_context();
return ret;
}
static int source_script(const char *path, int argc, char *argv[])
{
struct p_context ctx;
char *script;
int ret;
ctx.global_argc = argc;
ctx.global_argv = argv;
script = read_file(path, NULL);
if (!script) {
perror("sh");
return 1;
}
ret = parse_string_outer(&ctx, script, FLAG_PARSE_SEMICOLON);
free(script);
return ret;
}
int run_shell(void)
{
int rcode;
struct in_str input;
struct p_context ctx;
setup_file_in_str(&input);
rcode = parse_stream_outer(&ctx, &input, FLAG_PARSE_SEMICOLON);
return rcode;
}
static int do_sh(cmd_tbl_t *cmdtp, int argc, char *argv[])
{
if (argc < 2)
return COMMAND_ERROR_USAGE;
return execute_script(argv[1], argc - 1, argv + 1);
}
static const __maybe_unused char cmd_sh_help[] =
"Usage: sh filename [arguments]\n"
"\n"
"Execute a shell script\n";
BAREBOX_CMD_START(sh)
.cmd = do_sh,
.usage = "run shell script",
BAREBOX_CMD_HELP(cmd_sh_help)
BAREBOX_CMD_END
static int do_source(cmd_tbl_t *cmdtp, int argc, char *argv[])
{
if (argc < 2)
return COMMAND_ERROR_USAGE;
return source_script(argv[1], argc - 1, argv + 1);
}
static const char *source_aliases[] = { ".", NULL};
static const __maybe_unused char cmd_source_help[] =
"Usage: . filename [arguments]\n"
"or source filename [arguments]\n"
"\n"
"Read and execute commands from filename in the current shell\n"
"environment and return the exit status of the last command exe-\n"
"cuted from filename\n";
static const __maybe_unused char cmd_source_usage[] =
"execute shell script in current shell environment";
BAREBOX_CMD_START(source)
.aliases = source_aliases,
.cmd = do_source,
.usage = cmd_source_usage,
BAREBOX_CMD_HELP(cmd_source_help)
BAREBOX_CMD_END
/**
* @file
* @brief A prototype Bourne shell grammar parser
*/
/** @page sh_command Starting shell
*
* Usage: sh \<filename\> [\<arguments\>]
*
* Execute a shell script named \<filename\> and forward (if given)
* \<arguments\> to it.
*
* Usage: . \<filename\> [\<arguments\>]
* or source \<filename\> [\<arguments\>]
*
* Read and execute commands from \<filename\> in the current shell environment,
* forward (if given) \<arguments\> to it and return the exit status of the last
* command executed from filename.
*/
