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/* echo.c - simple example of a crash extension
*
* Copyright (C) 2001, 2002 Mission Critical Linux, Inc.
* Copyright (C) 2002-2005, 2007, 2013 David Anderson
* Copyright (C) 2002-2005, 2007, 2013 Red Hat, Inc. All rights reserved.
*
* 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
* (at your option) 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.
*/
#include "defs.h" /* From the crash source top-level directory */
static void echo_init(void); /* constructor function */
static void echo_fini(void); /* destructor function (optional) */
static void cmd_echo(void); /* Declare the commands and their help data. */
static char *help_echo[];
/*
* Please making the functions and global variables static within your
* extension if you don't want to make them visiable to subsequently
* loaded extensions. Otherwise, non-static symbols within 2 extensions
* that have the same name can cause confliction.
*/
static struct command_table_entry command_table[] = {
{ "echo", cmd_echo, help_echo, 0}, /* One or more commands, */
{ NULL }, /* terminated by NULL, */
};
static void __attribute__((constructor))
echo_init(void) /* Register the command set. */
{
register_extension(command_table);
}
/*
* This function is called if the shared object is unloaded.
* If desired, perform any cleanups here.
*/
static void __attribute__((destructor))
echo_fini(void) { }
/*
* Arguments are passed to the command functions in the global args[argcnt]
* array. See getopt(3) for info on dash arguments. Check out defs.h and
* other crash commands for usage of the myriad of utility routines available
* to accomplish what your task.
*/
static void
cmd_echo(void)
{
int c;
while ((c = getopt(argcnt, args, "")) != EOF) {
switch(c)
{
default:
argerrs++;
break;
}
}
if (argerrs)
cmd_usage(pc->curcmd, SYNOPSIS);
while (args[optind])
fprintf(fp, "%s ", args[optind++]);
fprintf(fp, "\n");
}
/*
* The optional help data is simply an array of strings in a defined format.
* For example, the "help echo" command will use the help_echo[] string
* array below to create a help page that looks like this:
*
* NAME
* echo - echoes back its arguments
*
* SYNOPSIS
* echo arg ...
*
* DESCRIPTION
* This command simply echoes back its arguments.
*
* EXAMPLE
* Echo back all command arguments:
*
* crash> echo hello, world
* hello, world
*
*/
static char *help_echo[] = {
"echo", /* command name */
"echoes back its arguments", /* short description */
"arg ...", /* argument synopsis, or " " if none */
" This command simply echoes back its arguments.",
"\nEXAMPLE",
" Echo back all command arguments:\n",
" crash> echo hello, world",
" hello, world",
NULL
};
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