cli: Add core dump info to core show settings.

Adds two pieces of information to the core show settings command
which are useful in the context of getting backtraces.

The first is to display whether or not Asterisk would generate
a core dump if it were to crash.

The second is to show the current running directory of Asterisk.

ASTERISK-29866 #close

Change-Id: Ic42c0a9ecc233381aad274d86c62808d1ebb4d83

Author: InterLinked1

main/asterisk.c

@@ -446,6 +446,23 @@ void ast_unregister_thread(void *id)
 	}
 }
 
+/*! \brief Print the contents of a file */
+static int print_file(int fd, char *desc, const char *filename)
+{
+	FILE *f;
+	char c;
+	if (!(f = fopen(filename, "r"))) {
+		return -1;
+	}
+	ast_cli(fd, "%s", desc);
+	while ((c = fgetc(f)) != EOF) {
+		ast_cli(fd, "%c", c);
+	}
+	fclose(f);
+	/* no need for trailing new line, the file already has one */
+	return 0;
+}
+
 /*! \brief Give an overview of core settings */
 static char *handle_show_settings(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
@@ -454,6 +471,9 @@ static char *handle_show_settings(struct ast_cli_entry *e, int cmd, struct ast_c
 	char eid_str[128];
 	struct rlimit limits;
 	char pbx_uuid[AST_UUID_STR_LEN];
+#if defined(HAVE_EACCESS) || defined(HAVE_EUIDACCESS)
+	char dir[PATH_MAX];
+#endif
 
 	switch (cmd) {
 	case CLI_INIT:
@@ -491,6 +511,8 @@ static char *handle_show_settings(struct ast_cli_entry *e, int cmd, struct ast_c
 	ast_cli(a->fd, "  Current console verbosity:   %d\n", ast_verb_console_get());
 	ast_cli(a->fd, "  Debug level:                 %d\n", option_debug);
 	ast_cli(a->fd, "  Trace level:                 %d\n", option_trace);
+	ast_cli(a->fd, "  Dump core on crash:          %s\n", ast_opt_dump_core ? "Yes" : "No");
+	print_file(a->fd, "  Core dump file:              ", "/proc/sys/kernel/core_pattern");
 	ast_cli(a->fd, "  Maximum load average:        %lf\n", ast_option_maxload);
 #if defined(HAVE_SYSINFO)
 	ast_cli(a->fd, "  Minimum free memory:         %ld MB\n", option_minmemfree);
@@ -510,6 +532,20 @@ static char *handle_show_settings(struct ast_cli_entry *e, int cmd, struct ast_c
 	ast_cli(a->fd, "  Default language:            %s\n", ast_defaultlanguage);
 	ast_cli(a->fd, "  Language prefix:             %s\n", ast_language_is_prefix ? "Enabled" : "Disabled");
 	ast_cli(a->fd, "  User name and group:         %s/%s\n", ast_config_AST_RUN_USER, ast_config_AST_RUN_GROUP);
+#if defined(HAVE_EACCESS) || defined(HAVE_EUIDACCESS)
+#if defined(HAVE_EUIDACCESS) && !defined(HAVE_EACCESS)
+#define eaccess euidaccess
+#endif
+	if (!getcwd(dir, sizeof(dir))) {
+		if (eaccess(dir, R_OK | X_OK | F_OK)) {
+			ast_cli(a->fd, "  Running directory:           %s\n", "Unable to access");
+		} else {
+			ast_cli(a->fd, "  Running directory:           %s (%s)\n", dir, "Unable to access");
+		}
+	} else {
+		ast_cli(a->fd, "  Running directory:           %s\n", dir);
+	}
+#endif /* defined(HAVE_EACCESS) || defined(HAVE_EUIDACCESS) */
 	ast_cli(a->fd, "  Executable includes:         %s\n", ast_test_flag(&ast_options, AST_OPT_FLAG_EXEC_INCLUDES) ? "Enabled" : "Disabled");
 	ast_cli(a->fd, "  Transcode via SLIN:          %s\n", ast_test_flag(&ast_options, AST_OPT_FLAG_TRANSCODE_VIA_SLIN) ? "Enabled" : "Disabled");
 	ast_cli(a->fd, "  Transmit silence during rec: %s\n", ast_test_flag(&ast_options, AST_OPT_FLAG_TRANSMIT_SILENCE) ? "Enabled" : "Disabled");
@@ -3861,9 +3897,6 @@ int main(int argc, char *argv[])
 
 	{
 #if defined(HAVE_EACCESS) || defined(HAVE_EUIDACCESS)
-#if defined(HAVE_EUIDACCESS) && !defined(HAVE_EACCESS)
-#define eaccess euidaccess
-#endif
 		char dir[PATH_MAX];
 		if (!getcwd(dir, sizeof(dir)) || eaccess(dir, R_OK | X_OK | F_OK)) {
 			fprintf(stderr, "Unable to access the running directory (%s).  Changing to '/' for compatibility.\n", strerror(errno));