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5700029c6

Denys Vlasenko

2018-01-12

SUCCESS Duration: 142s

Subject

hush: implement "command -v -V"

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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Build Log

(log yok)

Commit Diff GitHub →

shell/hush.c +84 -31

shell/hush.c+84 -31

@@ -47,18 +47,13 @@
	* follow IFS rules more precisely, including update semantics
	* tilde expansion
	* aliases
-	* builtins mandated by standards we don't support:
-	* [un]alias, command, fc:
-	* command -v CMD: print "/path/to/CMD"
-	* prints "CMD" for builtins
-	* prints "alias ALIAS='EXPANSION'" for aliases
-	* prints nothing and sets $? to 1 if not found
-	* command -V CMD: print "CMD is /path/CMD\|a shell builtin\|etc"
-	* command [-p] CMD: run CMD, even if a function CMD also exists
-	* (can use this to override standalone shell as well)
-	* -p: use default $PATH
+	* "command" missing features:
+	* command -p CMD: run CMD using default $PATH
+	* (can use this to override standalone shell as well?)
	* command BLTIN: disables special-ness (e.g. errors do not abort)
-	* NB: so far, only naked "command CMD" is implemented.
+	* command -V CMD1 CMD2 CMD3 (multiple args) (not in standard)
+	* builtins mandated by standards we don't support:
+	* [un]alias, fc:
	* fc -l[nr] [BEG] [END]: list range of commands in history
	* fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
	* fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
@@ -7337,6 +7332,30 @@ static void dump_cmd_in_x_mode(char **argv)
	# define dump_cmd_in_x_mode(argv) ((void)0)
	#endif

+	#if ENABLE_HUSH_COMMAND
+	static void if_command_vV_print_and_exit(char opt_vV, char cmd, const char explanation)
+	{
+	char *to_free;
+	if (!opt_vV)
+	return;
+
+	to_free = NULL;
+	if (!explanation) {
+	char *path = getenv("PATH");
+	explanation = to_free = find_executable(cmd, &path); /* path == NULL is ok */
+	if (opt_vV != 'V')
+	cmd = to_free; /* -v PROG prints "/path/to/PROG" */
+	}
+	if (explanation)
+	printf((opt_vV == 'V') ? "%s is %s\n" : "%s\n", cmd, explanation);
+	free(to_free);
+	fflush_all();
+	_exit(explanation == NULL); /* exit 1 if PROG was not found */
+	}
+	#else
+	# define if_command_vV_print_and_exit(a,b,c) ((void)0)
+	#endif
+
	#if BB_MMU
	#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
	pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
@@ -7357,7 +7376,11 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
	char **argv, int assignment_cnt,
	char **argv_expanded)
	{
+	const struct built_in_command *x;
	char **new_env;
+	#if ENABLE_HUSH_COMMAND
+	char opt_vV = 0;
+	#endif

	new_env = expand_assignments(argv, assignment_cnt);
	dump_cmd_in_x_mode(new_env);
@@ -7406,30 +7429,58 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
	}
	#endif

+	#if ENABLE_HUSH_COMMAND
+	/* "command BAR": run BAR without looking it up among functions
+	* "command -v BAR": print "BAR" or "/path/to/BAR"; or exit 1
+	* "command -V BAR": print "BAR is {a function,a shell builtin,/path/to/BAR}"
+	*/
+	while (strcmp(argv[0], "command") == 0 && argv[1]) {
+	char *p;
+
+	argv++;
+	p = *argv;
+	if (p[0] != '-' \|\| !p[1])
+	continue; /* bash allows "command command command [-OPT] BAR" */
+
+	for (;;) {
+	p++;
+	switch (*p) {
+	case '\0':
+	argv++;
+	p = *argv;
+	if (p[0] != '-' \|\| !p[1])
+	goto after_opts;
+	continue; /* next arg is also -opts, process it too */
+	case 'v':
+	case 'V':
+	opt_vV = *p;
+	continue;
+	default:
+	bb_error_msg_and_die("%s: %s: invalid option", "command", argv[0]);
+	}
+	}
+	}
+	after_opts:
+	# if ENABLE_HUSH_FUNCTIONS
+	if (opt_vV && find_function(argv[0]))
+	if_command_vV_print_and_exit(opt_vV, argv[0], "a function");
+	# endif
+	#endif
+
	/* Check if the command matches any of the builtins.
	* Depending on context, this might be redundant. But it's
	* easier to waste a few CPU cycles than it is to figure out
	* if this is one of those cases.
	*/
-	{
-	const struct built_in_command *x;
-
-	#if ENABLE_HUSH_COMMAND
-	/* This loop effectively makes "command BAR" run BAR without
-	* looking it up among functions.
-	*/
-	while (strcmp(argv[0], "command") == 0 && argv[1])
-	argv++;
-	//TODO: implement -Vvp and "disable dying if BAR is a builtin" behavior
-	#endif
-	/* On NOMMU, it is more expensive to re-execute shell
-	* just in order to run echo or test builtin.
-	* It's better to skip it here and run corresponding
-	* non-builtin later. */
-	x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
-	if (x) {
-	exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
-	}
+	/* Why "BB_MMU ? :" difference in logic? -
+	* On NOMMU, it is more expensive to re-execute shell
+	* just in order to run echo or test builtin.
+	* It's better to skip it here and run corresponding
+	* non-builtin later. */
+	x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
+	if (x) {
+	if_command_vV_print_and_exit(opt_vV, argv[0], "a shell builtin");
+	exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
	}

	#if ENABLE_FEATURE_SH_STANDALONE
@@ -7437,6 +7488,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
	{
	int a = find_applet_by_name(argv[0]);
	if (a >= 0) {
+	if_command_vV_print_and_exit(opt_vV, argv[0], "an applet");
	# if BB_MMU /* see above why on NOMMU it is not allowed */
	if (APPLET_IS_NOEXEC(a)) {
	/* Do not leak open fds from opened script files etc.
@@ -7466,6 +7518,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
	#if ENABLE_FEATURE_SH_STANDALONE \|\| BB_MMU
	skip:
	#endif
+	if_command_vV_print_and_exit(opt_vV, argv[0], NULL);
	execvp_or_die(argv);
	}

@@ -9895,7 +9948,7 @@ static int FAST_FUNC builtin_set(char **argv)

	/* Nothing known, so abort */
	error:
-	bb_error_msg("set: %s: invalid option", arg);
+	bb_error_msg("%s: %s: invalid option", "set", arg);
	return EXIT_FAILURE;
	}
	#endif