builtin.c

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#include "builtin.h"
 
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/io.h>
#include <sys/proc.h>
 
static uint64_t builtin_cd(uint64_t argc, const char** argv);
static uint64_t builtin_help(uint64_t argc, const char** argv);
static uint64_t builtin_clear(uint64_t argc, const char** argv);
 
static builtin_t builtins[] = {
    {
        .name = "cd",
        .callback = builtin_cd,
        .description = "Change the current working directory.",
        .usage = "cd [directory]",
    },
    {
        .name = "help",
        .callback = builtin_help,
        .description = "Show this help message.",
        .usage = "help",
    },
    {
        .name = "clear",
        .callback = builtin_clear,
        .description = "Clear the terminal screen.",
        .usage = "clear",
    },
};
 
static uint64_t builtin_cd(uint64_t argc, const char** argv)
{
    if (argc < 2)
    {
        chdir("/usr");
        return 0;
    }
 
    if (chdir(argv[1]) == ERR)
    {
        fprintf(stderr, "cd: %s\n", strerror(errno));
        return ERR;
    }
 
    return 0;
}
 
static uint64_t builtin_help(uint64_t argc, const char** argv)
{
    (void)argc;
    (void)argv;
 
    printf("\033[33mBUILTINS:\033[0m\n");
    for (uint64_t i = 0; i < sizeof(builtins) / sizeof(builtins[0]); i++)
    {
        printf("  %-20s\033[0m \t\033[90m%s\033[0m\n", builtins[i].usage, builtins[i].description);
    }
 
    printf("\n\033[33mFEATURES:\033[0m\n");
    printf("  command1 | command2\t\033[90mPipe output\033[0m\n");
    printf("  command > file     \t\033[90mRedirect standard output\033[0m\n");
    printf("  command < file     \t\033[90mRedirect standard input\033[0m\n");
    printf("  command 2> file    \t\033[90mRedirect standard error\033[0m\n");
    printf("\n\033[33mKEYBINDINGS:\033[0m\n");
    printf("  Back/Left/Right    \t\033[90mEdit input\033[0m\n");
    printf("  Up/Down            \t\033[90mNavigate history\033[0m\n");
    printf("  Ctrl+C             \t\033[90mTerminate process\033[0m\n");
 
    printf("\n\033[90mExternal commands are executed from /bin and /usr/bin.\033[0m\n");
 
    return 0;
}
 
static uint64_t builtin_clear(uint64_t argc, const char** argv)
{
    (void)argc;
    (void)argv;
 
    printf("\033[2J\033[H");
    return 0;
}
 
bool builtin_exists(const char* name)
{
    for (uint64_t i = 0; i < sizeof(builtins) / sizeof(builtins[0]); i++)
    {
        if (strcmp(name, builtins[i].name) == 0)
        {
            return true;
        }
    }
 
    return false;
}
 
uint64_t builtin_execute(uint64_t argc, const char** argv)
{
    if (argc == 0)
    {
        return 0;
    }
 
    for (uint64_t i = 0; i < sizeof(builtins) / sizeof(builtins[0]); i++)
    {
        if (strcmp(argv[0], builtins[i].name) == 0)
        {
            builtins[i].callback(argc, argv);
            return 0;
        }
    }
 
    return ERR;
}