/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <assert.h>
#include <gpxe/tables.h>
#include <gpxe/command.h>
#include <gpxe/settings.h>
/** @file
*
* Command execution
*
*/
static struct command commands[0]
__table_start ( struct command, commands );
static struct command commands_end[0]
__table_end ( struct command, commands );
/* Avoid dragging in getopt.o unless a command really uses it */
int optind;
int nextchar;
/**
* Execute command
*
* @v command Command name
* @v argv Argument list
* @ret rc Command exit status
*
* Execute the named command. Unlike a traditional POSIX execv(),
* this function returns the exit status of the command.
*/
int execv ( const char *command, char * const argv[] ) {
struct command *cmd;
int argc;
/* Count number of arguments */
for ( argc = 0 ; argv[argc] ; argc++ ) {}
/* Sanity checks */
if ( ! command ) {
DBG ( "No command\n" );
return -EINVAL;
}
if ( ! argc ) {
DBG ( "%s: empty argument list\n", command );
return -EINVAL;
}
/* Reset getopt() library ready for use by the command. This
* is an artefact of the POSIX getopt() API within the context
* of Etherboot; see the documentation for reset_getopt() for
* details.
*/
reset_getopt();
/* Hand off to command implementation */
for ( cmd = commands ; cmd < commands_end ; cmd++ ) {
if ( strcmp ( command, cmd->name ) == 0 )
return cmd->exec ( argc, ( char ** ) argv );
}
printf ( "%s: command not found\n", command );
return -ENOEXEC;
}
/**
* Expand variables within command line
*
* @v command Command line
* @ret expcmd Expanded command line
*
* The expanded command line is allocated with malloc() and the caller
* must eventually free() it.
*/
static char * expand_command ( const char *command ) {
char *expcmd;
char *start;
char *end;
char *head;
char *name;
char *tail;
int setting_len;
int new_len;
char *tmp;
/* Obtain temporary modifiable copy of command line */
expcmd = strdup ( command );
if ( ! expcmd )
return NULL;
/* Expand while expansions remain */
while ( 1 ) {
head = expcmd;
/* Locate opener */
start = strstr ( expcmd, "${" );
if ( ! start )
break;
*start = '\0';
name = ( start + 2 );
/* Locate closer */
end = strstr ( name, "}" );
if ( ! end )
break;
*end = '\0';
tail = ( end + 1 );
/* Determine setting length */
setting_len = fetchf_named_setting ( name, NULL, 0 );
if ( setting_len < 0 )
setting_len = 0; /* Treat error as empty setting */
/* Read setting into temporary buffer */
{
char setting_buf[ setting_len + 1 ];
setting_buf[0] = '\0';
fetchf_named_setting ( name, setting_buf,
sizeof ( setting_buf ) );
/* Construct expanded string and discard old string */
tmp = expcmd;
new_len = asprintf ( &expcmd, "%s%s%s",
head, setting_buf, tail );
free ( tmp );
if ( new_len < 0 )
return NULL;
}
}
return expcmd;
}
/**
* Split command line into argv array
*
* @v args Command line
* @v argv Argument array to populate, or NULL
* @ret argc Argument count
*
* Splits the command line into whitespace-delimited arguments. If @c
* argv is non-NULL, any whitespace in the command line will be
* replaced with NULs.
*/
static int split_args ( char *args, char * argv[] ) {
int argc = 0;
while ( 1 ) {
/* Skip over any whitespace / convert to NUL */
while ( *args == ' ' ) {
if ( argv )
*args = '\0';
args++;
}
/* Check for end of line */
if ( ! *args )
break;
/* We have found the start of the next argument */
if ( argv )
argv[argc] = args;
argc++;
/* Skip to start of next whitespace, if any */
while ( *args && ( *args != ' ' ) ) {
args++;
}
}
return argc;
}
/**
* Execute command line
*
* @v command Command line
* @ret rc Command exit status
*
* Execute the named command and arguments.
*/
int system ( const char *command ) {
char *args;
int argc;
int rc = 0;
/* Perform variable expansion */
args = expand_command ( command );
if ( ! args )
return -ENOMEM;
/* Count arguments */
argc = split_args ( args, NULL );
/* Create argv array and execute command */
if ( argc ) {
char * argv[argc + 1];
split_args ( args, argv );
argv[argc] = NULL;
if ( argv[0][0] != '#' )
rc = execv ( argv[0], argv );
}
free ( args );
return rc;
}
/**
* The "echo" command
*
* @v argc Argument count
* @v argv Argument list
* @ret rc Exit code
*/
static int echo_exec ( int argc, char **argv ) {
int i;
for ( i = 1 ; i < argc ; i++ ) {
printf ( "%s%s", ( ( i == 1 ) ? "" : " " ), argv[i] );
}
printf ( "\n" );
return 0;
}
/** "echo" command */
struct command echo_command __command = {
.name = "echo",
.exec = echo_exec,
};
