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1e660422b

Denys Vlasenko
Denys Vlasenko
2017-07-17
SUCCESS Duration: 143s

Subject

hush: implement "readonly" builtin

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

—

Build Log

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Commit Diff GitHub →

shell/hush.c +63 -36
shell/hush.c+63 -36
@@ -48,7 +48,7 @@
* tilde expansion
* aliases
* builtins mandated by standards we don't support:
- * [un]alias, command, fc, getopts, readonly, times:
+ * [un]alias, command, fc, getopts, times:
* command -v CMD: print "/path/to/CMD"
* prints "CMD" for builtins
* prints "alias ALIAS='EXPANSION'" for aliases
@@ -57,8 +57,7 @@
* 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
- * readonly VAR[=VAL]...: make VARs readonly
- * readonly [-p]: list all such VARs (-p has no effect in bash)
+ * command BLTIN: disables special-ness (e.g. errors do not abort)
* getopts: getopt() for shells
* times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
* fc -l[nr] [BEG] [END]: list range of commands in history
@@ -239,6 +238,12 @@
//config: help
//config: export -n unexports variables. It is a bash extension.
//config:
+//config:config HUSH_READONLY
+//config: bool "readonly builtin"
+//config: default y
+//config: help
+//config: Enable support for read-only variables.
+//config:
//config:config HUSH_KILL
//config: bool "kill builtin (supports kill %jobspec)"
//config: default y
@@ -964,6 +969,9 @@ static int builtin_exit(char **argv) FAST_FUNC;
#if ENABLE_HUSH_EXPORT
static int builtin_export(char **argv) FAST_FUNC;
#endif
+#if ENABLE_HUSH_READONLY
+static int builtin_readonly(char **argv) FAST_FUNC;
+#endif
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv) FAST_FUNC;
static int builtin_jobs(char **argv) FAST_FUNC;
@@ -1082,6 +1090,9 @@ static const struct built_in_command bltins1[] = {
#if ENABLE_HUSH_READ
BLTIN("read" , builtin_read , "Input into variable"),
#endif
+#if ENABLE_HUSH_READONLY
+ BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
+#endif
#if ENABLE_HUSH_FUNCTIONS
BLTIN("return" , builtin_return , "Return from function"),
#endif
@@ -2052,19 +2063,10 @@ static const char* FAST_FUNC get_local_var_value(const char *name)
* -1: clear export flag and unsetenv the variable
* flg_read_only is set only when we handle -R var=val
*/
-#if !BB_MMU && ENABLE_HUSH_LOCAL
-/* all params are used */
-#elif BB_MMU && ENABLE_HUSH_LOCAL
-#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
- set_local_var(str, flg_export, local_lvl)
-#elif BB_MMU && !ENABLE_HUSH_LOCAL
-#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
- set_local_var(str, flg_export)
-#elif !BB_MMU && !ENABLE_HUSH_LOCAL
-#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
- set_local_var(str, flg_export, flg_read_only)
-#endif
-static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
+static int set_local_var(char *str,
+ int flg_export UNUSED_PARAM,
+ int local_lvl UNUSED_PARAM,
+ int flg_read_only UNUSED_PARAM)
{
struct variable **var_pp;
struct variable *cur;
@@ -2088,9 +2090,7 @@ static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_
/* We found an existing var with this name */
if (cur->flg_read_only) {
-#if !BB_MMU
if (!flg_read_only)
-#endif
bb_error_msg("%s: readonly variable", str);
free(str);
return -1;
@@ -2158,10 +2158,12 @@ static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_
set_str_and_exp:
cur->varstr = str;
-#if !BB_MMU
- cur->flg_read_only = flg_read_only;
-#endif
exp:
+#if !BB_MMU || ENABLE_HUSH_READONLY
+ if (flg_read_only != 0) {
+ cur->flg_read_only = flg_read_only;
+ }
+#endif
if (flg_export == 1)
cur->flg_export = 1;
if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
@@ -9308,12 +9310,11 @@ static void print_escaped(const char *s)
}
#endif
-#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
-# if !ENABLE_HUSH_LOCAL
-#define helper_export_local(argv, exp, lvl) \
- helper_export_local(argv, exp)
-# endif
-static void helper_export_local(char **argv, int exp, int lvl)
+#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
+static int helper_export_local(char **argv,
+ int exp UNUSED_PARAM,
+ int ro UNUSED_PARAM,
+ int lvl UNUSED_PARAM)
{
do {
char *name = *argv;
@@ -9346,7 +9347,7 @@ static void helper_export_local(char **argv, int exp, int lvl)
}
}
# if ENABLE_HUSH_LOCAL
- if (exp == 0 /* local? */
+ if (exp == 0 && ro == 0 /* local? */
&& var && var->func_nest_level == lvl
) {
/* "local x=abc; ...; local x" - ignore second local decl */
@@ -9357,16 +9358,23 @@ static void helper_export_local(char **argv, int exp, int lvl)
* bash does not put it in environment,
* but remembers that it is exported,
* and does put it in env when it is set later.
- * We just set it to "" and export. */
+ * We just set it to "" and export.
+ */
/* Or, it's "local NAME" (without =VALUE).
- * bash sets the value to "". */
+ * bash sets the value to "".
+ */
+ /* Or, it's "readonly NAME" (without =VALUE).
+ * bash remembers NAME and disallows its creation
+ * in the future.
+ */
name = xasprintf("%s=", name);
} else {
/* (Un)exporting/making local NAME=VALUE */
name = xstrdup(name);
}
- set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
+ set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ ro);
} while (*++argv);
+ return EXIT_SUCCESS;
}
#endif
@@ -9412,9 +9420,7 @@ static int FAST_FUNC builtin_export(char **argv)
return EXIT_SUCCESS;
}
- helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
-
- return EXIT_SUCCESS;
+ return helper_export_local(argv, /*exp:*/ (opt_unexport ? -1 : 1), /*ro:*/ 0, /*lvl:*/ 0);
}
#endif
@@ -9425,11 +9431,32 @@ static int FAST_FUNC builtin_local(char **argv)
bb_error_msg("%s: not in a function", argv[0]);
return EXIT_FAILURE; /* bash compat */
}
- helper_export_local(argv, 0, G.func_nest_level);
- return EXIT_SUCCESS;
+ argv++;
+ return helper_export_local(argv, /*exp:*/ 0, /*ro:*/ 0, /*lvl:*/ G.func_nest_level);
}
#endif
+#if ENABLE_HUSH_READONLY
+static int FAST_FUNC builtin_readonly(char **argv)
+{
+ if (*++argv == NULL) {
+ /* bash: readonly [-p]: list all readonly VARs
+ * (-p has no effect in bash)
+ */
+ struct variable *e;
+ for (e = G.top_var; e; e = e->next) {
+ if (e->flg_read_only) {
+//TODO: quote value: readonly VAR='VAL'
+ printf("readonly %s\n", e->varstr);
+ }
+ }
+ return EXIT_SUCCESS;
+ }
+ return helper_export_local(argv, /*exp:*/ 0, /*ro:*/ 1, /*lvl:*/ 0);
+}
+#endif
+
+
#if ENABLE_HUSH_UNSET
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
static int FAST_FUNC builtin_unset(char **argv)