log: let command "log_output" to set back its default

The default log output is stderr. After the command "log_output"
has been used to set an output log file, it is possible to return
back to stderr only on *NIX hosts specifying a new log output file
as "/dev/stderr", but this is not intuitive, not documented and
not portable out of *NIX.

Make command "log_output" able to set back the default output to
stderr when the parameter is either "default" or is missing.
While there, add debug message to log the change and make the
command return error on incorrect syntax.

Change-Id: I8c7c929780f58e2c23936737c8e7274a96734786
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5233
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

diff --git a/doc/openocd.texi b/doc/openocd.texi
index de7dceb78cce083c999680f2235c74d6313e2aa6..d059cfae280a2c2526b0ff9814981b28d4468517 100644 (file)
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -7791,9 +7791,9 @@ echo "Downloading kernel -- please wait"
 @end example
 @end deffn
 
-@deffn Command log_output [filename]
-Redirect logging to @var{filename};
-the initial log output channel is stderr.
+@deffn Command log_output [filename | "default"]
+Redirect logging to @var{filename} or set it back to default output;
+the default log output channel is stderr.
 @end deffn
 
 @deffn Command add_script_search_dir [directory]

diff --git a/src/helper/log.c b/src/helper/log.c
index 8f48b928b5640791b1fd757be7d1150bdb24a742..ae26df5a1cf7c3913141c9de16ec92aa23e1eee1 100644 (file)
--- a/src/helper/log.c
+++ b/src/helper/log.c
@@ -220,6 +220,15 @@ COMMAND_HANDLER(handle_debug_level_command)
 
 COMMAND_HANDLER(handle_log_output_command)
 {
+       if (CMD_ARGC == 0 || (CMD_ARGC == 1 && strcmp(CMD_ARGV[0], "default") == 0)) {
+               if (log_output != stderr && log_output != NULL) {
+                       /* Close previous log file, if it was open and wasn't stderr. */
+                       fclose(log_output);
+               }
+               log_output = stderr;
+               LOG_DEBUG("set log_output to default");
+               return ERROR_OK;
+       }
        if (CMD_ARGC == 1) {
                FILE *file = fopen(CMD_ARGV[0], "w");
                if (file == NULL) {
@@ -231,9 +240,11 @@ COMMAND_HANDLER(handle_log_output_command)
                        fclose(log_output);
                }
                log_output = file;
+               LOG_DEBUG("set log_output to \"%s\"", CMD_ARGV[0]);
+               return ERROR_OK;
        }
 
-       return ERROR_OK;
+       return ERROR_COMMAND_SYNTAX_ERROR;
 }
 
 static const struct command_registration log_command_handlers[] = {
@@ -242,7 +253,7 @@ static const struct command_registration log_command_handlers[] = {
                .handler = handle_log_output_command,
                .mode = COMMAND_ANY,
                .help = "redirect logging to a file (default: stderr)",
-               .usage = "file_name",
+               .usage = "[file_name | \"default\"]",
        },
        {
                .name = "debug_level",