GMS Linux: start?

userprog/gmsh/Makefile

@@ -0,0 +1,17 @@
+# userprog/gmsh/Makefile
+
+TARGET = gmsh
+SRCS = gmsh.c builtin.c
+CC = gcc
+CFLAGS = -static -Wall
+
+OUT_BIN ?= $(TARGET)
+
+all: $(OUT_BIN)
+
+$(OUT_BIN): $(SRCS)
+	@echo "   [CC] Compiling to $(OUT_BIN)..."
+	$(CC) $(CFLAGS) -o $@ $^
+
+clean:
+	rm -f $(TARGET)

userprog/gmsh/builtin.c

@@ -0,0 +1,172 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/reboot.h>
+#include <sys/ioctl.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdbool.h>
+
+// #include "para.h"
+#include "builtin.h"
+
+
+void cmd_cd(char *path) { 
+    if (!path) path = "/";
+    if (chdir(path) != 0) perror("cd");
+}
+
+void cmd_pwd() { 
+    char buf[1024];
+    if(getcwd(buf, sizeof(buf))) printf("%s\n", buf); 
+}
+
+void cmd_ls(char *path) {
+    DIR *d = opendir(path ? path : ".");
+    struct dirent *dir;
+    if (d) {
+        while ((dir = readdir(d)) != NULL) if(dir->d_name[0] != '.') printf("%s  ", dir->d_name);
+        printf("\n"); closedir(d);
+    } else perror("ls");
+}
+
+// void cmd_cat(int argc, const char *argv[]) {
+//     if (argc < 2) {
+//         printf("Usage: cat <file1> [file2] ...\n");
+//         return;
+//     }
+
+//     char buf[1024];
+//     int n, fd;
+
+//     for (int i = 1; i < argc; i++) {
+//         fd = open(argv[i], O_RDONLY);
+        
+//         if (fd < 0) {
+//             perror(argv[i]); 
+//             continue;
+//         }
+
+//         while ((n = read(fd, buf, sizeof(buf))) > 0) {
+//             write(STDOUT_FILENO, buf, n);
+//         }
+        
+//         close(fd);
+//     }
+// }
+
+// void cmd_proc() {
+//     const int argc = 2;
+//     const char* args[] = {"cat", "/proc/cpuinfo", NULL};
+//     cmd_cat(argc, args);
+// }
+
+// void cmd_echo(int argc, const char *argv[]) {
+//     int start_index = 1;
+//     int no_newline = 0;
+
+//     if (argc > 1 && strcmp(argv[1], "-n") == 0) {
+//         no_newline = 1;
+//         start_index = 2;
+//     }
+
+//     for (int i = start_index; i < argc; i++) {
+//         printf("%s", argv[i]);
+        
+//         if (i < argc - 1) {
+//             printf(" ");
+//         }
+//     }
+
+//     if (!no_newline) {
+//         printf("\n");
+//     }
+
+//     fflush(stdout); 
+// }
+
+void cmd_poweroff() { sync(); reboot(RB_POWER_OFF); }
+void cmd_reboot() { sync(); reboot(RB_AUTOBOOT); }
+
+void cmd_size() {
+    struct winsize ws;
+
+    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0) {
+        printf("Terminal Size: %d rows x %d cols\n", ws.ws_row, ws.ws_col);
+    } else {
+        perror("size: failed to get window size");
+    }
+}
+
+void cmd_resize(char* row, char* col) {
+    struct winsize ws;
+    ws.ws_row = atoi(row);
+    ws.ws_col = atoi(col);
+    ws.ws_xpixel = 0;
+    ws.ws_ypixel = 0;
+
+    if (ioctl(STDOUT_FILENO, TIOCSWINSZ, &ws) == 0) {
+        printf("Terminal resized to %d x %d\n", ws.ws_row, ws.ws_col);
+    } else {
+        perror("resize failed");
+    }
+}
+
+void cmd_help() { printf("Built-ins: ls, cd, pwd, cat, sz, poweroff, reboot\n"); }
+
+void handle_redirection(const char *argv[]) {
+    int i = 0;
+    while (argv[i] != NULL) {
+        int fd = -1;
+        int is_redirect = 0;
+
+        // 1. Output Redirection (Overwrite): >
+        if (strcmp(argv[i], ">") == 0) {
+            if (argv[i+1] == NULL) {
+                fprintf(stderr, "gmsh: syntax error near unexpected token 'newline'\n");
+                exit(1);
+            }
+            fd = open(argv[i+1], O_WRONLY | O_CREAT | O_TRUNC, 0644);
+            if (fd < 0) { perror("open"); exit(1); }
+            
+            dup2(fd, STDOUT_FILENO); // stdout(1) -> fd
+            close(fd);
+            is_redirect = 1;
+        }
+        // 2. Output Redirection (Append): >>
+        else if (strcmp(argv[i], ">>") == 0) {
+            if (argv[i+1] == NULL) {
+                fprintf(stderr, "gmsh: syntax error\n");
+                exit(1);
+            }
+            // O_APPEND: 뒤에 추가
+            fd = open(argv[i+1], O_WRONLY | O_CREAT | O_APPEND, 0644);
+            if (fd < 0) { perror("open"); exit(1); }
+            
+            dup2(fd, STDOUT_FILENO);
+            close(fd);
+            is_redirect = 1;
+        }
+        // 3. Input Redirection: <
+        else if (strcmp(argv[i], "<") == 0) {
+            if (argv[i+1] == NULL) {
+                fprintf(stderr, "gmsh: syntax error\n");
+                exit(1);
+            }
+            fd = open(argv[i+1], O_RDONLY);
+            if (fd < 0) { perror("open"); exit(1); }
+            
+            dup2(fd, STDIN_FILENO); // stdin(0) -> fd
+            close(fd);
+            is_redirect = 1;
+        }
+
+        if (is_redirect) {
+            argv[i] = NULL;
+            break; 
+        }
+        i++;
+    }
+}

userprog/gmsh/builtin.h

@@ -0,0 +1,23 @@
+#ifndef BUILTIN_H
+#define BUILTIN_H
+
+void cmd_cd(char *path);
+void cmd_pwd();
+
+void cmd_ls(char *path);
+
+// void cmd_cat(int argc, const char* args[]);
+// void cmd_proc();
+// void cmd_echo(int argc, const char* args[]);
+
+void cmd_poweroff();
+void cmd_reboot();
+
+void cmd_size();
+void cmd_resize(char* row, char* col);
+
+void cmd_help();
+
+void handle_redirection(const char *argv[]);
+
+#endif // BUILTIN_H

userprog/gmsh/gmsh.c

@@ -0,0 +1,244 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/reboot.h>
+#include <sys/ioctl.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdbool.h>
+
+#include "para.h"
+#include "builtin.h"
+
+
+static bool verbose = false;
+
+int parse_cmd(char *cmd, char *argv[]) {
+    int argc = 0;
+    char *ptr = cmd;
+    char *token_start;
+    char quote_char = 0;
+
+    while (*ptr) {
+        while (*ptr == ' ' && quote_char == 0) ptr++;
+        if (*ptr == '\0') break;
+
+        token_start = ptr; 
+        char *write_ptr = ptr;
+
+        while (*ptr) {
+            if (quote_char == 0 && *ptr == ' ') {
+                ptr++; 
+                break;
+            }
+
+            if (*ptr == '"' || *ptr == '\'') {
+                if (quote_char == *ptr) quote_char = 0;
+                else if (quote_char == 0) quote_char = *ptr;
+                else *write_ptr++ = *ptr;
+            } 
+            else {
+                *write_ptr++ = *ptr;
+            }
+            
+            ptr++;
+        }
+        
+        *write_ptr = '\0';
+        argv[argc++] = token_start;
+
+        if (argc >= MAX_ARGS - 1) break;
+    }
+    
+    argv[argc] = NULL;
+    return argc;
+}
+
+// 반환값: 1(처리함), 0(파이프 없음)
+int handle_pipe(char *argv[]) {
+    int pipe_idx = -1;
+
+    // 1. 첫 번째 파이프 기호(|) 찾기
+    for (int i = 0; argv[i] != NULL; i++) {
+        if (strcmp(argv[i], "|") == 0) {
+            pipe_idx = i;
+            break;
+        }
+    }
+
+    // 파이프가 없으면 0 반환 (호출자가 일반 execvp 실행)
+    if (pipe_idx == -1) return 0;
+
+    // 2. 명령어 쪼개기
+    argv[pipe_idx] = NULL; // 파이프 기호를 NULL로 바꿔서 왼쪽 끊음
+    char **left_cmd = &argv[0];
+    char **right_cmd = &argv[pipe_idx + 1];
+
+    // 오른쪽 명령어가 없으면 에러 (예: "ls |")
+    if (right_cmd[0] == NULL) {
+        printf("gmsh: syntax error near unexpected token `|'\n");
+        return 1; 
+    }
+
+    // 3. 파이프 생성
+    int fds[2];
+    if (pipe(fds) == -1) {
+        perror("pipe");
+        return 1;
+    }
+
+    // 4. 왼쪽 자식 (Writer)
+    pid_t pid1 = fork();
+    if (pid1 == 0) {
+        close(fds[0]);   
+        dup2(fds[1], STDOUT_FILENO); 
+        close(fds[1]);   
+
+        handle_redirection((const char**) left_cmd);
+        execvp(left_cmd[0], left_cmd);
+        perror("execvp left");
+        exit(1);
+    }
+
+    // 5. 오른쪽 자식 (Reader + Recursion Manager)
+    pid_t pid2 = fork();
+    if (pid2 == 0) {
+        close(fds[1]);   
+        dup2(fds[0], STDIN_FILENO); // 입력 연결
+        close(fds[0]);   
+
+        // [핵심] 오른쪽 명령어에 또 파이프가 있는지 확인!
+        // 재귀 호출: 만약 파이프가 또 있다면 handle_pipe가 다시 fork를 뜨고 처리함
+        if (handle_pipe(right_cmd) == 1) {
+            // 재귀 호출 내부에서 자식들을 다 만들고 기다린 후 리턴했음.
+            // 이 중간 관리자 프로세스는 할 일을 다 했으므로 종료.
+            exit(0);
+        } 
+        else {
+            // 파이프가 더 이상 없으면 그냥 실행
+            handle_redirection((const char**) right_cmd);
+            execvp(right_cmd[0], right_cmd);
+            perror("execvp right");
+            exit(1);
+        }
+    }
+
+    // 6. 부모 프로세스
+    close(fds[0]);
+    close(fds[1]);
+
+    waitpid(pid1, NULL, 0);
+    waitpid(pid2, NULL, 0);
+
+    return 1; // 처리 완료
+}
+
+void run_shell() {
+    char cmd_buf[MAX_CMD_LEN];
+    char *args[MAX_ARGS];
+    char cwd[1024];
+    
+    while (1) {
+        if (getcwd(cwd, sizeof(cwd))) printf("\033[1;32mgmsh\033[0m:%s$ ", cwd);
+        else printf("gmsh:$ ");
+        fflush(stdout);
+
+        if (!fgets(cmd_buf, sizeof(cmd_buf), stdin)) break;
+        cmd_buf[strcspn(cmd_buf, "\n")] = 0;
+        if (strlen(cmd_buf) == 0) continue;
+
+        // int argc = 0;
+        // args[argc] = strtok(cmd_buf, " ");
+        // while (args[argc] != NULL && argc < MAX_ARGS - 1) args[++argc] = strtok(NULL, " ");
+
+        int argc = parse_cmd(cmd_buf, args);
+
+        if (argc == 0) continue;
+
+        if (handle_pipe(args)) {
+            continue;
+        }
+
+        if (verbose) {
+             printf("[debug] argc: %d\n", argc);
+             for(int i=0; i<argc; i++) printf("[debug] argv[%d]: '%s'\n", i, args[i]);
+        }
+
+        if (strcmp(args[0], "exit") == 0) exit(0);
+        else if (strcmp(args[0], "ls") == 0) cmd_ls(args[1]);
+        else if (strcmp(args[0], "cd") == 0) cmd_cd(args[1]);
+        else if (strcmp(args[0], "pwd") == 0) cmd_pwd();
+        // else if (strcmp(args[0], "cat") == 0) cmd_cat(argc, (const char**) args);
+        // else if (strcmp(args[0], "proc") == 0) cmd_proc();
+        // else if (strcmp(args[0], "echo") == 0) cmd_echo(argc, (const char**) args);
+
+        else if (strcmp(args[0], "size") == 0) cmd_size();
+        else if (strcmp(args[0], "resize") == 0){
+            if(argc != 3){
+                printf("Usage: resize <rows> <cols>\n");
+            }
+            else cmd_resize(args[1], args[2]);
+        }
+
+        else if (strcmp(args[0], "poweroff") == 0) cmd_poweroff();
+        else if (strcmp(args[0], "reboot") == 0) cmd_reboot();
+        else if (strcmp(args[0], "help") == 0) cmd_help();
+        else {
+            pid_t pid = fork();
+
+            // if (pid == 0) {
+            //     execvp(args[0], args);
+            //     printf("%s: command not found\n", args[0]);
+            //     exit(1);
+            // } else wait(NULL);
+	    
+            if (pid == 0) {
+                handle_redirection((const char**) args);
+                execvp(args[0], args);
+
+                fprintf(stderr, "%s: command not found\n", args[0]);
+                exit(127);
+            } else if (pid > 0) {
+                int status;
+
+                if (verbose) {
+                    printf("[debug] Spawned child PID: %d\n", pid);
+                }
+
+                waitpid(pid, &status, 0);
+
+                if (verbose) {
+                    if (WIFEXITED(status)) {
+                        printf("[debug] Process %d exited with code %d\n", pid, WEXITSTATUS(status));
+                    } else if (WIFSIGNALED(status)) {
+                        printf("[debug] Process %d killed by signal %d\n", pid, WTERMSIG(status));
+                    }
+                }
+            } else {
+                perror("fork");
+            }
+        }
+    }
+}
+
+int main(int argc, char** argv) {
+    printf("GMSH (GMS Minimal SHell) v1.0 initialized.\n");
+
+    int opt;
+    while ((opt = getopt(argc, argv, "v")) != -1) {
+        switch (opt) {
+            case 'v':
+                verbose = 1;
+                printf("[gmsh] Verbose mode enabled.\n");
+                break;
+            default:
+                fprintf(stderr, "Usage: %s [-v]\n", argv[0]);
+                exit(1);
+        }
+    }
+    
+    run_shell();
+    return 0;
+}

userprog/gmsh/para.h

@@ -0,0 +1,7 @@
+#ifndef PARA_H
+#define PARA_H
+
+#define MAX_CMD_LEN 1024
+#define MAX_ARGS 64
+
+#endif // PARA_H