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hush: heredoc support, based on patch by Mike Frysinger (vapier AT gentoo.org)

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some TODOs are to be attacked later

function                                             old     new   delta
parse_stream                                        1461    1866    +405
parse_redirect                                         -     265    +265
setup_heredoc                                          -     116    +116
setup_redirects                                      151     196     +45
builtin_exit                                          49      47      -2
redirect_opt_num                                      61      55      -6
setup_redirect                                       212       -    -212
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 2/2 up/down: 831/-220)          Total: 611 bytes
This commit is contained in:
Denis Vlasenko 2009-04-07 02:29:51 +00:00
parent ab2b064342
commit 6c9be7f451
4 changed files with 319 additions and 115 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

398
shell/hush.c
View File

@ -21,8 +21,8 @@
* rewrites.
*
* Other credits:
* o_addchr() derived from similar w_addchar function in glibc-2.2.
* setup_redirect(), redirect_opt_num(), and big chunks of main()
* o_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.
*
@ -249,11 +249,13 @@ static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
#define SPECIAL_VAR_SYMBOL 3
typedef enum redir_type {
REDIRECT_INVALID = 0,
REDIRECT_INPUT = 1,
REDIRECT_OVERWRITE = 2,
REDIRECT_APPEND = 3,
REDIRECT_HEREIS = 4,
REDIRECT_IO = 5
REDIRECT_HEREDOC = 4,
REDIRECT_IO = 5,
REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc load */
} redir_type;
/* The descrip member of this structure is only used to make
@ -263,12 +265,14 @@ static const struct {
signed char default_fd;
char descrip[3];
} redir_table[] = {
{ 0, 0, "()" },
{ 0, 0, "??" },
{ O_RDONLY, 0, "<" },
{ O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
{ O_RDONLY, -1, "<<" },
{ O_RDWR, 1, "<>" }
{ O_RDONLY, 0, "<<" },
{ O_CREAT|O_RDWR, 1, "<>" },
/* Should not be needed. Bogus default_fd helps in debugging */
/* { O_RDONLY, 77, "<<" }, */
};
typedef enum reserved_style {
@ -2030,20 +2034,56 @@ static char **expand_assignments(char **argv, int count)
}
//TODO: fix big string case!
static void setup_heredoc(int fd, const char *heredoc)
{
struct fd_pair pair;
pid_t pid;
xpiped_pair(pair);
pid = vfork();
if (pid < 0)
bb_perror_msg_and_die("vfork");
if (pid == 0) { /* child */
die_sleep = 0;
close(pair.rd);
xwrite_str(pair.wr, heredoc);
_exit(0);
}
/* parent */
die_sleep = -1;
close(pair.wr);
xmove_fd(pair.rd, fd);
}
/* squirrel != NULL means we squirrel away copies of stdin, stdout,
* and stderr if they are redirected. */
static int setup_redirects(struct command *prog, int squirrel[])
{
//TODO: no callers ever check return value - ?!
int openfd, mode;
struct redir_struct *redir;
for (redir = prog->redirects; redir; redir = redir->next) {
if (redir->dup == -1 && redir->rd_filename == NULL) {
/* something went wrong in the parse. Pretend it didn't happen */
if (redir->rd_type == REDIRECT_HEREDOC2) {
if (squirrel && redir->fd < 3) {
squirrel[redir->fd] = dup(redir->fd);
}
/* for REDIRECT_HEREDOC2, rd_filename holds _contents_
* of the heredoc */
debug_printf_parse("set heredoc '%s'\n",
redir->rd_filename);
setup_heredoc(redir->fd, redir->rd_filename);
continue;
}
if (redir->dup == -1) {
char *p;
if (redir->rd_filename == NULL) {
/* Something went wrong in the parse.
* Pretend it didn't happen */
continue;
}
mode = redir_table[redir->rd_type].mode;
//TODO: check redir for names like '\\'
p = expand_string_to_string(redir->rd_filename);
@ -2051,7 +2091,8 @@ static int setup_redirects(struct command *prog, int squirrel[])
free(p);
if (openfd < 0) {
/* this could get lost if stderr has been redirected, but
bash and ash both lose it as well (though zsh doesn't!) */
* bash and ash both lose it as well (though zsh doesn't!) */
//what the above comment tries to say?
return 1;
}
} else {
@ -3407,83 +3448,6 @@ static int run_and_free_list(struct pipe *pi)
}
/* Peek ahead in the in_str to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor.
* Return either -2 (syntax error), -1 (no &), or the number found.
*/
static int redirect_dup_num(struct in_str *input)
{
int ch, d = 0, ok = 0;
ch = i_peek(input);
if (ch != '&') return -1;
i_getch(input); /* get the & */
ch = i_peek(input);
if (ch == '-') {
i_getch(input);
return -3; /* "-" represents "close me" */
}
while (isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
i_getch(input);
ch = i_peek(input);
}
if (ok) return d;
bb_error_msg("ambiguous redirect");
return -2;
}
/* The src parameter allows us to peek forward to a possible &n syntax
* for file descriptor duplication, e.g., "2>&1".
* Return code is 0 normally, 1 if a syntax error is detected in src.
* Resource errors (in xmalloc) cause the process to exit */
static int setup_redirect(struct parse_context *ctx,
int fd,
redir_type style,
struct in_str *input)
{
struct command *command = ctx->command;
struct redir_struct *redir;
struct redir_struct **redirp;
int dup_num;
/* Check for a '2>&1' type redirect */
dup_num = redirect_dup_num(input);
if (dup_num == -2)
return 1; /* syntax error */
/* Create a new redir_struct and drop it onto the end of the linked list */
redirp = &command->redirects;
while ((redir = *redirp) != NULL) {
redirp = &(redir->next);
}
*redirp = redir = xzalloc(sizeof(*redir));
/* redir->next = NULL; */
/* redir->rd_filename = NULL; */
redir->rd_type = style;
redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
redir->dup = dup_num;
if (dup_num != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
} else {
/* We do _not_ try to open the file that src points to,
* since we need to return and let src be expanded first.
* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word. */
ctx->pending_redirect = redir;
}
return 0;
}
static struct pipe *new_pipe(void)
{
struct pipe *pi;
@ -3602,7 +3566,6 @@ static void initialize_context(struct parse_context *ctx)
done_command(ctx);
}
/* If a reserved word is found and processed, parse context is modified
* and 1 is returned.
*/
@ -3766,14 +3729,26 @@ static int done_word(o_string *word, struct parse_context *ctx)
if (ctx->pending_redirect) {
/* We do not glob in e.g. >*.tmp case. bash seems to glob here
* only if run as "bash", not "sh" */
/* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
* "2.7 Redirection
* ...the word that follows the redirection operator
* shall be subjected to tilde expansion, parameter expansion,
* command substitution, arithmetic expansion, and quote
* removal. Pathname expansion shall not be performed
* on the word by a non-interactive shell; an interactive
* shell may perform it, but shall do so only when
* the expansion would result in one word."
*/
ctx->pending_redirect->rd_filename = xstrdup(word->data);
word->o_assignment = NOT_ASSIGNMENT;
debug_printf("word stored in rd_filename: '%s'\n", word->data);
debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
} else {
/* "{ echo foo; } echo bar" - bad */
/* NB: bash allows e.g.:
* if true; then { echo foo; } fi
* while if false; then false; fi do break; done
* and disallows:
* while if false; then false; fi; do; break; done
* TODO? */
if (command->group) {
syntax(word->data);
@ -3855,6 +3830,117 @@ static int done_word(o_string *word, struct parse_context *ctx)
return 0;
}
/* Peek ahead in the input to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor.
* Return: -3 if >&- "close fd" construct is seen,
* -2 (syntax error), -1 if no & was seen, or the number found.
*/
#if BB_MMU
#define redirect_dup_num(as_string, input) \
redirect_dup_num(input)
#endif
static int redirect_dup_num(o_string *as_string, struct in_str *input)
{
int ch, d, ok;
ch = i_peek(input);
if (ch != '&')
return -1;
ch = i_getch(input); /* get the & */
#if !BB_MMU
o_addchr(as_string, ch);
#endif
ch = i_peek(input);
if (ch == '-') {
ch = i_getch(input);
#if !BB_MMU
o_addchr(as_string, ch);
#endif
return -3; /* "-" represents "close me" */
}
d = 0;
ok = 0;
while (ch != EOF && isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
ch = i_getch(input);
#if !BB_MMU
o_addchr(as_string, ch);
#endif
ch = i_peek(input);
}
if (ok) return d;
//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
bb_error_msg("ambiguous redirect");
return -2;
}
/* Return code is 0 normally, 1 if a syntax error is detected
*/
static int parse_redirect(struct parse_context *ctx,
int fd,
redir_type style,
struct in_str *input)
{
struct command *command = ctx->command;
struct redir_struct *redir;
struct redir_struct **redirp;
int dup_num;
dup_num = -1;
if (style != REDIRECT_HEREDOC) {
/* Check for a '2>&1' type redirect */
dup_num = redirect_dup_num(&ctx->as_string, input);
if (dup_num == -2)
return 1; /* syntax error */
}
//TODO: else { check for <<-word }
if (style == REDIRECT_OVERWRITE && dup_num == -1) {
int ch = i_peek(input);
if (ch == '|') {
/* >|FILE redirect ("clobbering" >).
* Since we do not support "set -o noclobber" yet,
* >| and > are the same for now. Just eat |.
*/
ch = i_getch(input);
#if !BB_MMU
o_addchr(&ctx->as_string, ch);
#endif
}
}
/* Create a new redir_struct and append it to the linked list */
redirp = &command->redirects;
while ((redir = *redirp) != NULL) {
redirp = &(redir->next);
}
*redirp = redir = xzalloc(sizeof(*redir));
/* redir->next = NULL; */
/* redir->rd_filename = NULL; */
redir->rd_type = style;
redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf_parse("redirect type %d %s\n", redir->fd, redir_table[style].descrip);
redir->dup = dup_num;
if (dup_num != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf_parse("duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
} else {
/* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word. */
ctx->pending_redirect = redir;
}
return 0;
}
/* If a redirect is immediately preceded by a number, that number is
* supposed to tell which file descriptor to redirect. This routine
* looks for such preceding numbers. In an ideal world this routine
@ -3863,25 +3949,97 @@ static int done_word(o_string *word, struct parse_context *ctx)
* echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
* echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
* echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
* A -1 output from this program means no valid number was found, so the
* caller should use the appropriate default for this redirection.
*
* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
* "2.7 Redirection
* ... If n is quoted, the number shall not be recognized as part of
* the redirection expression. For example:
* echo \2>a
* writes the character 2 into file a"
* I am not sure we do it right (and not sure we care)
*
* A -1 return means no valid number was found,
* the caller should use the appropriate default for this redirection.
*/
static int redirect_opt_num(o_string *o)
{
int num;
if (o->length == 0)
if (o->data == NULL)
return -1;
num = bb_strtou(o->data, NULL, 10);
if (errno || num < 0)
return -1;
for (num = 0; num < o->length; num++) {
if (!isdigit(o->data[num])) {
return -1;
}
}
num = atoi(o->data);
o_reset(o);
return num;
}
//TODO: add NOMMU as_string fill
static char *fetch_till_str(struct in_str *input, const char *word)
{
o_string heredoc = NULL_O_STRING;
int past_EOL = 0;
int ch;
while (1) {
ch = i_getch(input);
if (ch == EOF) {
o_free_unsafe(&heredoc);
return NULL;
}
if (ch == '\n') {
if (strcmp(heredoc.data + past_EOL, word) == 0) {
heredoc.data[past_EOL] = '\0';
debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
return heredoc.data;
}
past_EOL = heredoc.length + 1;
}
o_addchr(&heredoc, ch);
}
}
static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
{
struct pipe *pi = ctx->list_head;
while (pi) {
int i;
struct command *cmd = pi->cmds;
debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
pi->num_cmds,
cmd->argv ? cmd->argv[0] : "NONE");
for (i = 0; i < pi->num_cmds; i++) {
struct redir_struct *redirect = cmd->redirects;
debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
i, cmd->argv ? cmd->argv[0] : "NONE");
while (redirect) {
if (redirect->rd_type == REDIRECT_HEREDOC) {
char *p;
if (heredoc_cnt <= 0)
return 1; /* error */
redirect->rd_type = REDIRECT_HEREDOC2;
p = fetch_till_str(input, redirect->rd_filename);
if (!p)
return 1; /* unexpected EOF */
free(redirect->rd_filename);
redirect->rd_filename = p;
heredoc_cnt--;
}
redirect = redirect->next;
}
cmd++;
}
pi = pi->next;
}
/* Should be 0. If it isn't, it's a parse error */
return heredoc_cnt;
}
#if BB_MMU
#define parse_stream(pstring, input, end_trigger) \
parse_stream(input, end_trigger)
@ -4391,8 +4549,7 @@ static int parse_stream_dquoted(o_string *as_string,
again:
ch = i_getch(input);
#if !BB_MMU
if (as_string && ch != EOF)
o_addchr(as_string, ch);
if (as_string && ch != EOF) o_addchr(as_string, ch);
#endif
if (ch == dquote_end) { /* may be only '"' or EOF */
dest->nonnull = 1;
@ -4479,6 +4636,7 @@ static struct pipe *parse_stream(char **pstring,
struct parse_context ctx;
o_string dest = NULL_O_STRING;
int is_in_dquote;
int heredoc_cnt;
/* Double-quote state is handled in the state variable is_in_dquote.
* A single-quote triggers a bypass of the main loop until its mate is
@ -4498,6 +4656,7 @@ static struct pipe *parse_stream(char **pstring,
/* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
initialize_context(&ctx);
is_in_dquote = 0;
heredoc_cnt = 0;
while (1) {
const char *is_ifs;
const char *is_special;
@ -4518,6 +4677,11 @@ static struct pipe *parse_stream(char **pstring,
ch, ch, dest.o_escape);
if (ch == EOF) {
struct pipe *pi;
if (heredoc_cnt) {
syntax("unterminated here document");
goto parse_error;
}
if (done_word(&dest, &ctx)) {
goto parse_error;
}
@ -4578,14 +4742,36 @@ static struct pipe *parse_stream(char **pstring,
#endif
/* Treat newline as a command separator. */
done_pipe(&ctx, PIPE_SEQ);
debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
if (heredoc_cnt) {
if (fetch_heredocs(heredoc_cnt, &ctx, input))
goto parse_error;
heredoc_cnt = 0;
}
dest.o_assignment = MAYBE_ASSIGNMENT;
ch = ';';
/* note: if (is_ifs) continue;
* will still trigger for us */
}
}
if (end_trigger && end_trigger == ch) {
if (end_trigger && end_trigger == ch
&& (heredoc_cnt == 0 || end_trigger != ';')
) {
//TODO: disallow "{ cmd }" without semicolon
if (heredoc_cnt) {
/* This is technically valid:
* { cat <<HERE; }; echo Ok
* heredoc
* heredoc
* heredoc
* HERE
* but we don't support this.
* We require heredoc to be in enclosing {}/(),
* if any.
*/
syntax("unterminated here document");
goto parse_error;
}
if (done_word(&dest, &ctx)) {
goto parse_error;
}
@ -4715,7 +4901,8 @@ static struct pipe *parse_stream(char **pstring,
goto parse_error;
}
#endif
setup_redirect(&ctx, redir_fd, redir_style, input);
if (parse_redirect(&ctx, redir_fd, redir_style, input))
goto parse_error;
break;
case '<':
redir_fd = redirect_opt_num(&dest);
@ -4724,7 +4911,9 @@ static struct pipe *parse_stream(char **pstring,
}
redir_style = REDIRECT_INPUT;
if (next == '<') {
redir_style = REDIRECT_HEREIS;
redir_style = REDIRECT_HEREDOC;
heredoc_cnt++;
debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
ch = i_getch(input);
#if !BB_MMU
o_addchr(&ctx.as_string, ch);
@ -4742,7 +4931,8 @@ static struct pipe *parse_stream(char **pstring,
goto parse_error;
}
#endif
setup_redirect(&ctx, redir_fd, redir_style, input);
if (parse_redirect(&ctx, redir_fd, redir_style, input))
goto parse_error;
break;
case ';':
#if ENABLE_HUSH_CASE

22
shell/hush_test/hush-misc/exec.tests
View File

@ -1,30 +1,30 @@
# make sure we have a way of checking these things
[ ! -e /dev/fd ] && exit 1
cd /proc/$$/fd || cd /dev/fd || exit 1
[ -e /dev/fd/44 ] && exit 1
[ -e 44 ] && exit 1
exec 44>/dev/null
[ -e /dev/fd/44 ] || exit 1
[ -e 44 ] || exit 1
echo pass fd out open
[ -e /dev/fd/55 ] && exit 1
[ -e 55 ] && exit 1
exec 55>&44
[ -e /dev/fd/55 ] || exit 1
[ -e 55 ] || exit 1
echo pass fd out dup
exec 44>&-
[ -e /dev/fd/44 ] && exit 1
[ -e 44 ] && exit 1
echo pass fd out close
[ -e /dev/fd/66 ] && exit 1
[ -e 66 ] && exit 1
exec 66</dev/null
[ -e /dev/fd/66 ] || exit 1
[ -e 66 ] || exit 1
echo pass fd in open
[ -e /dev/fd/77 ] && exit 1
[ -e 77 ] && exit 1
exec 77<&66
[ -e /dev/fd/77 ] || exit 1
[ -e 77 ] || exit 1
echo pass fd in dup
exec 66<&-
[ -e /dev/fd/66 ] && exit 1
[ -e 66 ] && exit 1
echo pass fd in close

5
shell/hush_test/hush-misc/heredoc1.right Normal file
View File

@ -0,0 +1,5 @@
qwe
asd
123
456
Ok

9
shell/hush_test/hush-misc/heredoc1.tests Executable file
View File

@ -0,0 +1,9 @@
cat <<000; cat <<www; cat <<eee
000
qwe
asd
www
123
456
eee
echo Ok