On Fri, Jun 25, 2010 at 08:51:12PM +0200, Vladimir 'φ-coder/phcoder' Serbinenko wrote: > Colin Watson wrote: > > On Fri, Jun 18, 2010 at 11:34:08AM -0700, Josh Triplett wrote: > >> The "cat" command, if given a file with DOS line endings, will show the > >> \r at the end of every line as a control character. For convenience, > >> please consider adding support for this in "cat", ideally automatically. > > > > Makes sense to me. grub-devel, how about this patch? > > Unconditionaly stripping \r is a bad idea because sometimes cat in grub > is used to determine why the system fails to boot. And if by a stupid > action fstab becomes DOS-formated 'cat /etc/fstab' will fail to show > this important point. But it's ok to add an option for cat'ing DOS > files.
OK. How about the following patch, then? > In this case we probably need to mark unix newlines somehow to > detect a reverse problem I think we can live without this. It adds complexity (I can't immediately think of a neat way to represent this visually) and I think it would be needed quite rarely. Besides, I was looking around for examples and noticed that when vim is in DOS mode it simply treats both \r\n and \n as newlines. That seems a good enough precedent for me. 2010-06-20 Colin Watson <[email protected]> * commands/cat.c (options): New variable. (grub_cmd_cat): Parse options. If the --dos option is given, print DOS-style "\r\n" line endings as simple newlines. (GRUB_MOD_INIT): Use extcmd. (GRUB_MOD_FINI): Likewise. * docs/grub.texi (cat): Document --dos. === modified file 'commands/cat.c' --- commands/cat.c 2010-03-01 19:24:34 +0000 +++ commands/cat.c 2010-06-27 23:56:11 +0000 @@ -23,19 +23,28 @@ #include <grub/term.h> #include <grub/misc.h> #include <grub/gzio.h> -#include <grub/command.h> +#include <grub/extcmd.h> #include <grub/i18n.h> -static grub_err_t -grub_cmd_cat (grub_command_t cmd __attribute__ ((unused)), - int argc, char **args) +static const struct grub_arg_option options[] = + { + {"dos", -1, 0, N_("Accept DOS-style CR/NL line endings."), 0, 0}, + {0, 0, 0, 0, 0, 0} + }; +static grub_err_t +grub_cmd_cat (grub_extcmd_t cmd, int argc, char **args) { + struct grub_arg_list *state = cmd->state; + int dos = 0; grub_file_t file; char buf[GRUB_DISK_SECTOR_SIZE]; grub_ssize_t size; int key = 0; + if (state[0].set) + dos = 1; + if (argc != 1) return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name required"); @@ -54,6 +63,11 @@ grub_cmd_cat (grub_command_t cmd __attri if ((grub_isprint (c) || grub_isspace (c)) && c != '\r') grub_putchar (c); + else if (dos && c == '\r' && buf[i + 1] == '\n') + { + grub_putchar ('\n'); + i++; + } else { grub_setcolorstate (GRUB_TERM_COLOR_HIGHLIGHT); @@ -74,15 +88,16 @@ grub_cmd_cat (grub_command_t cmd __attri return 0; } -static grub_command_t cmd; +static grub_extcmd_t cmd; GRUB_MOD_INIT(cat) { - cmd = grub_register_command_p1 ("cat", grub_cmd_cat, - N_("FILE"), N_("Show the contents of a file.")); + cmd = grub_register_extcmd ("cat", grub_cmd_cat, GRUB_COMMAND_FLAG_BOTH, + N_("FILE"), N_("Show the contents of a file."), + options); } GRUB_MOD_FINI(cat) { - grub_unregister_command (cmd); + grub_unregister_extcmd (cmd); } === modified file 'docs/grub.texi' --- docs/grub.texi 2010-06-26 09:50:39 +0000 +++ docs/grub.texi 2010-06-27 23:45:11 +0000 @@ -1624,13 +1624,19 @@ a menu entry). @node cat @subsection cat -...@deffn Command cat file +...@deffn Command cat [...@option{--dos}] file Display the contents of the file @var{file}. This command may be useful to remind you of your OS's root partition: @example grub> @kbd{cat /etc/fstab} @end example + +If the @option{--dos} option is used, then carriage return / new line pairs +will be displayed as a simple new line. Otherwise, the carriage return will +be displayed as a control character (@samp{<d>}) to make it easier to see +when boot problems are caused by a file formatted using DOS-style line +endings. @end deffn Thanks, -- Colin Watson [[email protected]] -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
