Re: [PATCH 2/2] add detailed help messages to btrfs command

[Goffredo Baroncelli <kreijack@libero.it>]

Hello Hubert,

please update the man page too.

Regards
G.Baroncelli

On 01/23/2011 01:42 PM, Hubert Kario wrote:
> extend the
> 
>         btrfs <cmd> --help
> 
> command to print detailed help message if available but fallback to
> basic help message if detailed is unavailable
> 
> add detailed help message for 'filesystem defragment' command
> 
> little tweaks in comments
> 
> Signed-off-by: Hubert Kario <kario@wit.edu.pl>
> ---
>  btrfs.c |  101 ++++++++++++++++++++++++++++++++++++++++++--------------------
>  1 files changed, 68 insertions(+), 33 deletions(-)
> 
> diff --git a/btrfs.c b/btrfs.c
> index b84607a..bd6f6f8 100644
> --- a/btrfs.c
> +++ b/btrfs.c
> @@ -23,6 +23,9 @@
>  #include "btrfs_cmds.h"
>  #include "version.h"
>  
> +#define BASIC_HELP 0
> +#define ADVANCED_HELP 1
> +
>  typedef int (*CommandFunction)(int argc, char **argv);
>  
>  struct Command {
> @@ -31,8 +34,10 @@ struct Command {
>  				   if >= 0, number of arguments,
>  				   if < 0, _minimum_ number of arguments */
>  	char	*verb;		/* verb */
> -	char	*help;		/* help lines; form the 2nd onward they are
> -				   indented */
> +	char	*help;		/* help lines; from the 2nd line onward they 
> +                                   are automatically indented */
> +        char    *adv_help;      /* advanced help message; from the 2nd line 
> +                                   onward they are automatically indented */
>  
>  	/* the following fields are run-time filled by the program */
>  	char	**cmds;		/* array of subcommands */
> @@ -47,73 +52,96 @@ static struct Command commands[] = {
>  	{ do_clone, 2,
>  	  "subvolume snapshot", "<source> [<dest>/]<name>\n"
>  		"Create a writable snapshot of the subvolume <source> with\n"
> -		"the name <name> in the <dest> directory."
> +		"the name <name> in the <dest> directory.",
> +          NULL
>  	},
>  	{ do_delete_subvolume, 1,
>  	  "subvolume delete", "<subvolume>\n"
> -		"Delete the subvolume <subvolume>."
> +		"Delete the subvolume <subvolume>.",
> +          NULL
>  	},
>  	{ do_create_subvol, 1,
>  	  "subvolume create", "[<dest>/]<name>\n"
>  		"Create a subvolume in <dest> (or the current directory if\n"
> -		"not passed)."
> +		"not passed).",
> +          NULL
>  	},
>  	{ do_subvol_list, 1, "subvolume list", "<path>\n"
> -		"List the snapshot/subvolume of a filesystem."
> +		"List the snapshot/subvolume of a filesystem.",
> +          NULL
>  	},
>  	{ do_find_newer, 2, "subvolume find-new", "<path> <last_gen>\n"
> -		"List the recently modified files in a filesystem."
> +		"List the recently modified files in a filesystem.",
> +          NULL
>  	},
>  	{ do_defrag, -1,
>  	  "filesystem defragment", "[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
> -		"Defragment a file or a directory."
> +		"Defragment a file or a directory.",
> +          "[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
> +          "Defragment file data or directory metadata.\n"
> +                "-v         be verbose\n"
> +                "-c         compress the file while defragmenting\n"
> +                "-f         flush data to disk immediately after defragmenting\n"
> +                "-s start   defragment only from byte onward\n"
> +                "-l len     defragment only up to len bytes\n"
> +                "-t size    minimal size of file to be considered for defragmenting\n"
>  	},
>  	{ do_set_default_subvol, 2,
>  	  "subvolume set-default", "<id> <path>\n"
>  		"Set the subvolume of the filesystem <path> which will be mounted\n"
> -		"as default."
> +		"as default.",
> +          NULL
>  	},
>  	{ do_fssync, 1,
>  	  "filesystem sync", "<path>\n"
> -		"Force a sync on the filesystem <path>."
> +		"Force a sync on the filesystem <path>.",
> +          NULL
>  	},
>  	{ do_resize, 2,
>  	  "filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
>  		"Resize the file system. If 'max' is passed, the filesystem\n"
> -		"will occupe all available space on the device."
> +		"will occupe all available space on the device.",
> +          NULL
>  	},
>  	{ do_show_filesystem, 999,
>  	  "filesystem show", "[<uuid>|<label>]\n"
>  		"Show the info of a btrfs filesystem. If no <uuid> or <label>\n"
> -		"is passed, info of all the btrfs filesystem are shown."
> +		"is passed, info of all the btrfs filesystem are shown.",
> +          NULL
>  	},
>  	{ do_df_filesystem, 1,
>  	  "filesystem df", "<path>\n"
> -		"Show space usage information for a mount point\n."
> +		"Show space usage information for a mount point.",
> +          NULL
>  	},
>  	{ do_balance, 1,
>  	  "filesystem balance", "<path>\n"
> -		"Balance the chunks across the device."
> +		"Balance the chunks across the device.",
> +          NULL
>  	},
>  	{ do_scan,
>  	  999, "device scan", "[<device> [<device>..]\n"
>  		"Scan all device for or the passed device for a btrfs\n"
> -		"filesystem."
> +		"filesystem.",
> +          NULL
>  	},
>  	{ do_add_volume, -2,
>  	  "device add", "<dev> [<dev>..] <path>\n"
> -		"Add a device to a filesystem."
> +		"Add a device to a filesystem.",
> +          NULL
>  	},
>  	{ do_remove_volume, -2,
>  	  "device delete", "<dev> [<dev>..] <path>\n"
> -		"Remove a device from a filesystem."
> +		"Remove a device from a filesystem.",
> +          NULL
>  	},
>  	/* coming soon
>  	{ 2, "filesystem label", "<label> <path>\n"
> -		"Set the label of a filesystem"
> +		"Set the label of a filesystem",
> +          NULL
>  	}
>  	*/
> -	{ 0, 0 , 0 }
> +	{ 0, 0, 0, 0 }
>  };
>  
>  static char *get_prgname(char *programname)
> @@ -128,17 +156,25 @@ static char *get_prgname(char *programname)
>  	return np;
>  }
>  
> -static void print_help(char *programname, struct Command *cmd)
> +static void print_help(char *programname, struct Command *cmd, int helptype)
>  {
>  	char	*pc;
>  
>  	printf("\t%s %s ", programname, cmd->verb );
>  
> -	for(pc = cmd->help; *pc; pc++){
> -		putchar(*pc);
> -		if(*pc == '\n')
> -			printf("\t\t");
> -	}
> +        if (helptype == ADVANCED_HELP && cmd->adv_help)
> +                for(pc = cmd->adv_help; *pc; pc++){
> +                        putchar(*pc);
> +                        if(*pc == '\n')
> +                                printf("\t\t");
> +                }
> +        else
> +	        for(pc = cmd->help; *pc; pc++){
> +		        putchar(*pc);
> +		        if(*pc == '\n')
> +			        printf("\t\t");
> +	        }
> +
>  	putchar('\n');
>  }
>  
> @@ -148,10 +184,10 @@ static void help(char *np)
>  
>  	printf("Usage:\n");
>  	for( cp = commands; cp->verb; cp++ )
> -		print_help(np, cp);
> +		print_help(np, cp, BASIC_HELP);
>  
>  	printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
> -	printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or\n\t\t"
> +	printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or"
>              "subset of commands.\n",np);
>  	printf("\n%s\n", BTRFS_BUILD_VERSION);
>  }
> @@ -257,15 +293,14 @@ static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd
>  
>  
>  /*
> -
> -	This function perform the following jobs:
> +	This function performs the following jobs:
>  	- show the help if '--help' or 'help' or '-h' are passed
>  	- verify that a command is not ambiguous, otherwise show which
>  	  part of the command is ambiguous
> -	- if after a (even partial) command there is '--help' show the help
> +	- if after a (even partial) command there is '--help' show detailed help
>  	  for all the matching commands
> -	- if the command doesn't' match show an error
> -	- finally, if a command match, they return which command is matched and
> +	- if the command doesn't match show an error
> +	- finally, if a command matches, they return which command matched and
>  	  the arguments
>  
>  	The function return 0 in case of help is requested; <0 in case
> @@ -319,7 +354,7 @@ static int parse_args(int argc, char **argv,
>  		if(argc>i+1 && !strcmp(argv[i+1],"--help")){
>  			if(!helprequested)
>  				printf("Usage:\n");
> -			print_help(prgname, cp);
> +			print_help(prgname, cp, ADVANCED_HELP);
>  			helprequested=1;
>  			continue;
>  		}