[Crash-utility] [PATCH V2] extensions: add extend -s option to show all available shared object file

[Dave Anderson]

Thanks Wang -- queued for crash-7.2.9:

  https://github.com/crash-utility/crash/commit/5dfbc7aa27392a095b207d31654cec7db94dd810
  
Dave


----- Original Message -----
> When we load extensions, sometime we do not know the exact name of the shared
> object file.
>  
> This patch add -s option for extend cmd to show all available shared object
> file.
> 
> for example:
> 
> crash> extend -s
> ./trace.so
> /usr/lib64/crash/extensions/dminfo.so
> /usr/lib64/crash/extensions/echo.so
> /usr/lib64/crash/extensions/eppic.so
> /usr/lib64/crash/extensions/snap.so
> /usr/lib64/crash/extensions/trace.so
> ./extensions/dminfo.so
> ./extensions/eppic.so
> ./extensions/echo.so
> ./extensions/snap.so
> ./extensions/trace.so
> crash> extend -s -l
> extend: -l and -s are mutually exclusive
> Usage:
>   extend [shared-object ...] | [-u [shared-object ...]] | -s
> Enter "help extend" for details.
> crash> extend -s -u
> extend: -u and -s are mutually exclusive
> Usage:
>   extend [shared-object ...] | [-u [shared-object ...]] | -s
> Enter "help extend" for details.
> crash>
> 
> Also, this patch update the help for extend command:
> add the search order "5. the ./extensions subdirectory of the current
> directory"
> 
> Changes since v1:
> - -s option also check the current working directory
> - fix warning
> 
> Signed-off-by: Wang Long <w at laoqinren.net>
> ---
>  extensions.c | 75
>  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
>  help.c       |  4 +++-
>  2 files changed, 74 insertions(+), 5 deletions(-)
> 
> diff --git a/extensions.c b/extensions.c
> index 24b91de..d23b1e3 100644
> --- a/extensions.c
> +++ b/extensions.c
> @@ -20,10 +20,13 @@
>  
>  static int in_extensions_library(char *, char *);
>  static char *get_extensions_directory(char *);
> +static void show_all_extensions(void);
> +static void show_extensions(char *);
>  
> -#define DUMP_EXTENSIONS   (0)
> -#define LOAD_EXTENSION    (1)
> -#define UNLOAD_EXTENSION  (2)
> +#define DUMP_EXTENSIONS        (0)
> +#define LOAD_EXTENSION         (1)
> +#define UNLOAD_EXTENSION       (2)
> +#define SHOW_ALL_EXTENSIONS    (4)
>  
>  /*
>   *  Load, unload, or list the extension libaries.
> @@ -36,14 +39,30 @@ cmd_extend(void)
>  
>  	flag = DUMP_EXTENSIONS;
>  
> -        while ((c = getopt(argcnt, args, "lu")) != EOF) {
> +        while ((c = getopt(argcnt, args, "lus")) != EOF) {
>                  switch(c)
>                  {
> +		case 's':
> +			if (flag & UNLOAD_EXTENSION) {
> +				error(INFO,
> +					"-s and -u are mutually exclusive\n");
> +				argerrs++;
> +			}else if (flag & LOAD_EXTENSION) {
> +				error(INFO,
> +					"-s and -l are mutually exclusive\n");
> +				argerrs++;
> +			} else
> +				flag |= SHOW_ALL_EXTENSIONS;
> +			break;
>  		case 'l':
>  			if (flag & UNLOAD_EXTENSION) {
>  				error(INFO,
>  					"-l and -u are mutually exclusive\n");
>  				argerrs++;
> +			} else if (flag & SHOW_ALL_EXTENSIONS) {
> +				error(INFO,
> +					"-l and -s are mutually exclusive\n");
> +				argerrs++;
>  			} else
>  				flag |= LOAD_EXTENSION;
>  			break;
> @@ -53,6 +72,10 @@ cmd_extend(void)
>                                  error(INFO,
>                                          "-u and -l are mutually
>                                          exclusive\n");
>                                  argerrs++;
> +			} else if (flag & SHOW_ALL_EXTENSIONS) {
> +				error(INFO,
> +					"-u and -s are mutually exclusive\n");
> +				argerrs++;
>                          } else
>                                  flag |= UNLOAD_EXTENSION;
>  			break;
> @@ -100,6 +123,11 @@ cmd_extend(void)
>  			optind++;
>  		}
>  		break;
> +
> +	case SHOW_ALL_EXTENSIONS:
> +		show_all_extensions();
> +		break;
> +
>  	}
>  }
>  
> @@ -182,6 +210,45 @@ dump_extension_table(int verbose)
>  	} while ((ext = ext->prev));
>  }
>  
> +static void
> +show_extensions(char *dir) {
> +	DIR *dirp;
> +	struct dirent *dp;
> +	char filename[BUFSIZE*2];
> +
> +        dirp = opendir(dir);
> +	if (!dirp)
> +		return;
> +
> +        for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) {
> +		sprintf(filename, "%s%s%s", dir,
> +			LASTCHAR(dir) == '/' ? "" : "/",
> +			dp->d_name);
> +
> +		if (!is_shared_object(filename))
> +			continue;
> +		fprintf(fp, "%s\n", filename);
> +	}
> +
> +	closedir(dirp);
> +}
> +
> +static void
> +show_all_extensions(void)
> +{
> +	char *dir;
> +
> +	show_extensions("./");
> +
> +	if ((dir = getenv("CRASH_EXTENSIONS")))
> +		show_extensions(dir);
> +
> +	if (BITS64())
> +		show_extensions("/usr/lib64/crash/extensions/");
> +
> +	show_extensions("/usr/lib/crash/extensions/");
> +	show_extensions("./extensions/");
> +}
>  
>  /*
>   *  Load an extension library.
> diff --git a/help.c b/help.c
> index a481850..a0ebe42 100644
> --- a/help.c
> +++ b/help.c
> @@ -2164,13 +2164,14 @@ NULL
>  char *help_extend[] = {
>  "extend",
>  "extend the %s command set",
> -"[shared-object ...] | [-u [shared-object ...]]",
> +"[shared-object ...] | [-u [shared-object ...]] | -s",
>  "  This command dynamically loads or unloads %s extension shared object",
>  "  libraries:\n",
>  "    shared-object     load the specified shared object file; more than
>  one",
>  "                      one object file may be entered.",
>  "    -u shared-object  unload the specified shared object file; if no file",
>  "                      arguments are specified, unload all objects.",
> +"    -s                show all available shared object file.",
>  "\n  If the shared-object filename is not expressed with a fully-qualified",
>  "  pathname, the following directories will be searched in the order
>  shown,",
>  "  and the first instance of the file that is found will be selected:\n",
> @@ -2178,6 +2179,7 @@ char *help_extend[] = {
>  "     2. the directory specified in the CRASH_EXTENSIONS environment
>  variable",
>  "     3. /usr/lib64/crash/extensions (64-bit architectures)",
>  "     4. /usr/lib/crash/extensions",
> +"     5. the ./extensions subdirectory of the current directory",
>  "\n  If no arguments are entered, the current set of shared object files and
>  ",
>  "  a list of their commands will be displayed.  The registered commands",
>  "  contained in each shared object file will appear automatically in the ",
> --
> 1.8.3.1
> 
> 
> 
>