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#include <stdio.h>
#include <stdlib.h>
#include <console.h>
#include <string.h>
#include <sys/module.h>
#include <sys/exec.h>
#define INFO_PRINT(fmt, args...) printf("[COM32] " fmt, ##args)
#define MAX_COMMAND_SIZE 80 // Maximum size of the cmd line
#define COMMAND_DELIM " \t\n" // Whitespace delimiters
#define MAX_COMMAND_ARGS (MAX_COMMAND_SIZE/2) // Maximum argument count for
// program execution
/**
* print_help - Display usage instructions on the screen.
*/
static void print_help(void)
{
printf("List of available commands:\n");
printf("exit - exits the program\n");
printf("help - shows this message\n");
printf("load <library>... - loads the libraries into the environment\n");
printf("spawn <executable> <args> - launches an executable module\n");
printf
("unload <library>... - unloads the libraries from the environment\n");
printf("list - prints the currently loaded modules\n");
}
/**
* print_prompt - Display the command prompt.
*/
static void print_prompt(void)
{
printf("\nelflink> ");
}
/**
* read_command - Read a new command from the standard input.
* @cmd: the buffer to store the command
* @size: the maximum size of the string that can be stored in the buffer
*
* If the command is larger than the specified size, it is truncated.
*/
static void read_command(char *cmd, int size)
{
char *nl = NULL;
fgets(cmd, size, stdin);
// Strip the newline
nl = strchr(cmd, '\n');
if (nl != NULL)
*nl = '\0';
}
/**
* process_spawn - Handles the execution of a 'spawn' command.
*
* The command line is in the internal buffer of strtok.
*/
static void process_spawn(void)
{
// Compose the command line
char **cmd_line = malloc((MAX_COMMAND_ARGS + 1) * sizeof(char *));
int argc = 0, result;
char *crt_arg;
do {
crt_arg = strtok(NULL, COMMAND_DELIM);
if (crt_arg != NULL && strlen(crt_arg) > 0) {
cmd_line[argc] = crt_arg;
argc++;
} else {
break;
}
} while (argc < MAX_COMMAND_ARGS);
cmd_line[argc] = NULL;
if (cmd_line[0] == NULL) {
printf("You must specify an executable module.\n");
} else {
result = spawnv(cmd_line[0], cmd_line);
printf("Spawn returned %d\n", result);
}
free(cmd_line);
}
/**
* process_library - Handles the execution of the 'load' and 'unload' commands.
* @load: contains 1 if the libraries are to be loaded, 0 for unloading.
*
* The command line is in the internal buffer of strtok.
*/
static void process_library(int load)
{
char *crt_lib;
int result;
while ((crt_lib = strtok(NULL, COMMAND_DELIM)) != NULL) {
if (strlen(crt_lib) > 0) {
if (load)
result = load_library(crt_lib);
else
result = unload_library(crt_lib);
if (result == 0) {
printf("Library '%s' %sloaded successfully.\n", crt_lib,
load ? "" : "un");
} else {
printf("Could not %sload library '%s': error %d\n",
load ? "" : "un", crt_lib, result);
}
}
}
}
/**
* process_list - Handles the execution of the 'list' command.
*
*/
static void process_list(void)
{
struct elf_module *module;
struct module_dep *crt_dep;
for_each_module(module) {
printf("%s (%dK, %s, %s) : ", module->name, module->module_size >> 10,
module->shallow ? "shallow" : "regular",
module->main_func == NULL ? "library" : "program");
list_for_each_entry(crt_dep, &module->required, list) {
printf("%s ", crt_dep->module->name);
}
printf("\n");
}
}
/**
* process_command - Recognizes the requested command and executes it.
* @cmd: the command to be executed.
*
* Returns 1 if the command was 'exit', 0 otherwise.
*/
static int process_command(char *cmd)
{
char *cmd_name;
cmd_name = strtok(cmd, COMMAND_DELIM);
if (strcmp(cmd_name, "exit") == 0) {
printf("Goodbye!\n");
return 1;
} else if (strcmp(cmd_name, "help") == 0) {
print_help();
} else if (strcmp(cmd_name, "load") == 0) {
process_library(1);
} else if (strcmp(cmd_name, "spawn") == 0) {
process_spawn();
} else if (strcmp(cmd_name, "unload") == 0) {
process_library(0);
} else if (strcmp(cmd_name, "list") == 0) {
process_list();
} else {
printf("Unknown command. Type 'help' for a list of valid commands.\n");
}
return 0;
}
/**
* The entry point of 'test_com32' COM module.
*/
int main(int argc, char **argv)
{
int done = 0;
int res;
char command[MAX_COMMAND_SIZE] = { 0 };
// Open a standard r/w console
openconsole(&dev_stdcon_r, &dev_stdcon_w);
res = exec_init();
if (res != 0) {
printf("Failed to initialize the execution environment.\n");
return res;
} else {
printf("Execution environment initialized successfully.\n");
}
printf("\nFor a list of available commands, type 'help'.\n");
do {
print_prompt();
read_command(command, MAX_COMMAND_SIZE);
done = process_command(command);
} while (!done);
exec_term();
return 0;
}
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