};
-/* Normal */
static void maybe_die(const char *notice, const char *msg)
{
/* Was using fancy stuff:
#define syntax(msg) _syntax(msg, __LINE__)
#endif
+
static int glob_needed(const char *s)
{
while (*s) {
* sigset_t blocked_set: current blocked signal set
*
* "trap - SIGxxx":
- * clear bit in blocked_set unless it is also in non_DFL
+ * clear bit in blocked_set unless it is also in non_DFL_mask
* "trap 'cmd' SIGxxx":
* set bit in blocked_set (even if 'cmd' is '')
* after [v]fork, if we plan to be a shell:
struct command *command,
char **argv_expanded)
{
- if (command->argv)
- pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
+ if (command->argv) {
+ pseudo_exec_argv(nommu_save, command->argv,
+ command->assignment_cnt, argv_expanded);
+ }
if (command->group) {
-#if !BB_MMU
- bb_error_msg_and_die("nested lists are not supported on NOMMU");
-#else
+ /* Cases when we are here:
+ * ( list )
+ * { list } &
+ * ... | ( list ) | ...
+ * ... | { list } | ...
+ */
+#if BB_MMU
int rcode;
debug_printf_exec("pseudo_exec: run_list\n");
rcode = run_list(command->group);
/* OK to leak memory by not calling free_pipe_list,
* since this process is about to exit */
_exit(rcode);
+#else
+//TODO: re-exec "hush -c command->group_as_a_string"
+ bb_error_msg_and_die("nested lists are not supported on NOMMU");
#endif
}
/* Can happen. See what bash does with ">foo" by itself. */
- debug_printf("trying to pseudo_exec null command\n");
+ debug_printf("pseudo_exec'ed null command\n");
_exit(EXIT_SUCCESS);
}
/* run_pipe() 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
+ * 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 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.
- *
* Returns -1 only if started some children. IOW: we have to
* mask out retvals of builtins etc with 0xff!
+ *
+ * The only case when we do not need to [v]fork is when the pipe
+ * is single, non-backgrounded, non-subshell command. Examples:
+ * cmd ; ... { list } ; ...
+ * cmd && ... { list } && ...
+ * cmd || ... { list } || ...
+ * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
+ * or (if SH_STANDALONE) an applet, and we can run the { list }
+ * with run_list(). Otherwise, we fork and exec cmd.
+ *
+ * Cases when we must fork:
+ * non-single: cmd | cmd
+ * backgrounded: cmd & { list } &
+ * subshell: ( list ) [&]
*/
static int run_pipe(struct pipe *pi)
{
+ static const char *const null_ptr = NULL;
int i;
int nextin;
int pipefds[2]; /* pipefds[0] is for reading */
struct command *command;
char **argv_expanded;
char **argv;
- const struct built_in_command *x;
char *p;
/* it is not always needed, but we aim to smaller code */
int squirrel[] = { -1, -1, -1 };
int rcode;
- const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
- debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
+ debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
-#if ENABLE_HUSH_JOB
- pi->pgrp = -1;
-#endif
- pi->alive_cmds = 1;
+ USE_HUSH_JOB(pi->pgrp = -1;)
pi->stopped_cmds = 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.
- */
command = &(pi->cmds[0]);
+ argv_expanded = NULL;
-#if ENABLE_HUSH_FUNCTIONS
- if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
- /* We "execute" function definition */
- bb_error_msg("here we ought to remember function definition, and go on");
- return EXIT_SUCCESS;
+ if (pi->num_cmds != 1
+ || pi->followup == PIPE_BG
+ || command->grp_type == GRP_SUBSHELL
+ ) {
+ goto must_fork;
}
-#endif
- if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
- debug_printf("non-subshell grouping\n");
+ pi->alive_cmds = 1;
+
+ debug_printf_exec(": group:%p argv:'%s'\n",
+ command->group, command->argv ? command->argv[0] : "NONE");
+
+ if (command->group) {
+#if ENABLE_HUSH_FUNCTIONS
+ if (command->grp_type == GRP_FUNCTION) {
+ /* func () { list } */
+ bb_error_msg("here we ought to remember function definition, and go on");
+ return EXIT_SUCCESS;
+ }
+#endif
+ /* { list } */
+ debug_printf("non-subshell group\n");
setup_redirects(command, squirrel);
debug_printf_exec(": run_list\n");
rcode = run_list(command->group) & 0xff;
return rcode;
}
- argv = command->argv;
- argv_expanded = NULL;
-
- if (single_and_fg && argv != NULL) {
+ argv = command->argv ? command->argv : (char **) &null_ptr;
+ {
+ const struct built_in_command *x;
char **new_env = NULL;
char **old_env = NULL;
- i = command->assignment_cnt;
- if (i != 0 && argv[i] == NULL) {
- /* assignments, but no command: set local environment */
- for (i = 0; argv[i] != NULL; i++) {
- debug_printf("local environment set: %s\n", argv[i]);
- p = expand_string_to_string(argv[i]);
+ if (argv[command->assignment_cnt] == NULL) {
+ /* Assignments, but no command */
+ /* Ensure redirects take effect. Try "a=t >file" */
+ setup_redirects(command, squirrel);
+ restore_redirects(squirrel);
+ /* Set shell variables */
+ while (*argv) {
+ p = expand_string_to_string(*argv);
+ debug_printf_exec("set shell var:'%s'->'%s'\n",
+ *argv, p);
set_local_var(p, 0);
+ argv++;
}
- return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
+ /* Do we need to flag set_local_var() errors?
+ * "assignment to readonly var" and "putenv error"
+ */
+ return EXIT_SUCCESS;
}
/* Expand the rest into (possibly) many strings each */
- argv_expanded = expand_strvec_to_strvec(argv + i);
+ argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
if (strcmp(argv_expanded[0], x->cmd) != 0)
goto clean_up_and_ret;
}
#endif
+ /* It is neither builtin nor applet. We must fork. */
}
+ must_fork:
/* NB: argv_expanded may already be created, and that
* might include `cmd` runs! Do not rerun it! We *must*
* use argv_expanded if it's non-NULL */
if (command->argv) {
debug_printf_exec(": pipe member '%s' '%s'...\n",
command->argv[0], command->argv[1]);
- } else
+ } else {
debug_printf_exec(": pipe member with no argv\n");
+ }
/* pipes are inserted between pairs of commands */
pipefds[0] = 0;
projects / oweals / busybox.git / commitdiff