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authorDenys Vlasenko2018-01-12 14:41:45 +0100
committerDenys Vlasenko2018-01-12 14:41:45 +0100
commit5700029c65f2218b5fceca77a9140aff6d882aab (patch)
tree39c98b5ad7a7b0eab4ec18e4111b8b6677066f19
parentcca7c611f26d98415c0f986e5a5e731ab5e379ff (diff)
downloadbusybox-5700029c65f2218b5fceca77a9140aff6d882aab.zip
busybox-5700029c65f2218b5fceca77a9140aff6d882aab.tar.gz
hush: implement "command -v -V"
function old new delta pseudo_exec_argv 231 374 +143 if_command_vV_print_and_exit - 127 +127 builtin_set 267 273 +6 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 2/0 up/down: 276/0) Total: 276 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--shell/hush.c115
1 files changed, 84 insertions, 31 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 93779ba..196bdbe 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -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