9 files changed, 251 insertions, 210 deletions

diff --git a/.gitignore b/.gitignore
index 66c7e33..d26e08e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 *
 !*.*
 !*/*
+.vscode/*
 !Makefile
 *.o
 *.tab*
diff --git a/Makefile b/Makefile
index c052fe9..3a3da47 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,11 @@
-bcsh: syntax.tab.o bcsh.c
-        gcc -g -o bcsh bcsh.c syntax.tab.o -lfl
+bcsh: syntax.tab.o bcsh.o cmd.o
+        gcc -g -o bcsh bcsh.o cmd.o syntax.tab.o -lfl
+
+bcsh.o: bcsh.c
+        gcc -g -c bcsh.c -o bcsh.o
+
+cmd.o: cmd.c
+        gcc -g -c cmd.c -o cmd.o
 
 syntax.tab.o: lex.yy.c syntax.tab.c
         gcc -g -c syntax.tab.c -o syntax.tab.o
@@ -11,4 +17,6 @@ syntax.tab.c: syntax.y
         bison -o syntax.tab.c -d -v syntax.y -Wcounterexamples
 
 clean:
-        rm -f bcsh lex.yy.c syntax.tab.c syntax.tab.h syntax.output syntax.tab.o
+        rm -f bcsh
+        rm -f bcsh.o cmd.o syntax.tab.o
+        rm -f lex.yy.c syntax.tab.c syntax.tab.h syntax.output
diff --git a/README.md b/README.md
index d75af6d..e882907 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,6 @@
-[toc]
-
 # 我与 shell
 
-我是个喜欢用 Linux 命令行的人，**喜欢用命令行来完成一切工作，喜欢这种自己独掌系统一切的感觉**，仿佛自己是这台电脑的创世神~~，虽然现实中我只是废柴一个~~。对于每个学习 Linux 的人来说，bash 绝对是一座绕不过去的山，即使已有了 zsh、fish shell 等更加现代化、更加友好的工具，bash 由于其普适性和强大的功能，依然是大多数生产环境的首选。
+我是个喜欢用 Linux 命令行的人，**喜欢用命令行来完成一切工作，喜欢这种自己独掌系统一切的感觉**，仿佛自己是这台电脑的创世神（虽然现实中只是废柴一个）。对于每个学习 Linux 的人来说，bash 绝对是一座绕不过去的山，即使已有了 zsh、fish shell 等更加现代化、更加友好的工具，bash 由于其普适性和强大的功能，依然是大多数生产环境的首选。
 
 但我在学 bash 时遇到了不小的困难，我发现 bash 的语法规定过于奇怪繁杂，完全不像其他编程语言，甚至就连 if 和括号之间都要求必须插入空格，第一次学的时候我在这里犯错，还找了好久。相比之下，我更喜欢 C 语言的语法（也许是我计算机入门学的就是 C 的缘故吧），多简洁明了啊！
 
@@ -10,7 +8,7 @@
 
 在学习 Linux-0.12 的过程中，我第一次了解到，**原来 shell 和我们自己编写的其他程序一样，是一个独立于操作系统之外的用户态程序**，因而是可以替换的、甚至是可以自己编写的。本来这件事遥遥无期，也许一辈子都不会去做，但我偏偏遇到了网络信息技术大赛，看到了开源鸿蒙 Terminal 应用开发这条赛道。嗯……shell 开发怎么不算 Terminal 应用开发呢？（笑。）于是一个计划生根发芽。
 
-我的计划是这样的：**我要自己编写一个 shell，这个 shell 要能够完全替代 bash，而且要比 bash 更加简洁易用**。这个 shell 的名字就叫 bcsh，意为“Better C Shell”。我希望通过这个 shell 的开发，能够更加深入地了解 shell 的工作原理，同时也能够提高自己的编程能力。
+我的计划是这样的：**我要自己编写一个 shell，这个 shell 要能够完全替代 bash，而且要比 bash 更加简洁易用**。我希望通过这个 shell 的开发，能够更加深入地了解 shell 的工作原理，同时也能够提高自己的编程能力。
 
 我的设计初衷是，在基本命令与功能上，尽可能地贴近 bash，以免影响我自己的使用习惯；同时，在 case、if、循环等语法上，向 C 语言靠拢，让初学者（主要是我自己）更容易上手。当然，我也会在这个过程中，尽可能地保持代码的简洁性和可读性。因而我为它取了"bcsh"这个名字：
 
@@ -29,7 +27,7 @@
 
 ## TODO list
 
-- Ctrl+C、Ctrl+D、Ctrl+Z 等信号的处理
+- Ctrl+Z 等信号的处理
 - 复杂语法的支持：if、case、循环等
 - 设置与显示环境变量
 - 命令历史记录
diff --git a/bcsh.c b/bcsh.c
index 656d608..f1f6b42 100644
--- a/bcsh.c
+++ b/bcsh.c
@@ -19,199 +19,30 @@ int main(int argc, char **argv) {
 }
 
 void showPrompt() {
-    printf("\033[01;32m%s"
-           "\033[35m@%s\033[00m:"
-           "\033[33m%s\033[00m$ ",
-           username, hostname, pwd);
-    fflush(stdout);
-}
-
-Command *newCmd() {
-    Command *cmd = (Command *)malloc(sizeof(Command));
-    cmd->argc = 0;
-    cmd->args = NULL;
-    cmd->type = CMD_NORMAL;
-    cmd->left = NULL;
-    cmd->right = NULL;
-    for (int i = 0; i < 3; i++) {
-        cmd->redirectFile[i] = NULL;
-        cmd->redirectFD[i] = i;
-    }
-    cmd->background = false;
-    return cmd;
-}
-
-int runCmd(Command *cmd) {
-    int status;
-    if (cmd == NULL) {
-        fprintf(stderr, "cmd is NULL\n");
-        return -1;
-    }
-    switch (cmd->type) {
-    case CMD_NORMAL:
-        status = runNormalCmd(cmd);
-        break;
-    case CMD_PIPE:
-        status = runPipeCmd(cmd);
-        break;
-    case CMD_AND:
-    case CMD_OR:
-        status = runAndOrCmd(cmd);
-        break;
-    }
-
-    freeCmd(cmd);
-    return status;
-}
-
-int runNormalCmd(Command *cmd) {
-    pid_t pid;
-    int status;
-    if (!strcmp(cmd->args[0], "exit")) {
-        printf("Good Bye, %s!\n", username);
-        exit(0);
-    } else if (!strcmp(cmd->args[0], "cd")) {
-        if (cmd->argc == 1) {
-            chdir(getenv("HOME"));
-        } else {
-            chdir(cmd->args[1]);
-        }
-        printf("\r");
-        getcwd(pwd, sizeof(pwd));
+    if (getuid() == 0) {
+        printf("%s@%s:%s# ", username, hostname, pwd);
     } else {
-        if ((pid = fork()) == 0) {
-            // consider the redirection now
-            // it's just a part of normal command
-            // but not in other types
-            redirect(cmd);
-            exit(execvp(cmd->args[0], cmd->args));
-        } else {
-            if (!cmd->background) {
-                waitpid(pid, &status, 0);
-                if (!WIFEXITED(status)) {
-                    // when here, the child process exited abnormally
-                    fprintf(stderr, "Process %d exited with status %d\n", pid,
-                            WEXITSTATUS(status));
-                }
-            }
-        }
-        // return the exit status of the child process
-        return WEXITSTATUS(status);
-    }
-}
-
-int runPipeCmd(Command *cmd) {
-    int status;
-    // create a pipe file and gets two file descriptors
-    // fd[0] is the read end, while fd[1] the write end
-    int fd[2];
-    pid_t left, right;
-    pipe(fd);
-    if ((left = fork()) == 0) {
-        /*
-         * close the read end of the pipe, so that the child process
-         * can only write to it; then redirect the standard output
-         * to the write end of the pipe, and close the write end
-         * itself as a file descriptor.
-         */
-        close(fd[0]);
-        dup2(fd[1], 1);
-        close(fd[1]);
-        exit(runCmd(cmd->left));
-    }
-    if ((right = fork()) == 0) {
-        close(fd[1]);
-        dup2(fd[0], 0);
-        close(fd[0]);
-        exit(runCmd(cmd->right));
-    }
-    // close the pipe, because the parent process doesn't need it
-    // and wait for the two child processes to exit
-    close(fd[0]);
-    close(fd[1]);
-    waitpid(left, NULL, 0);
-    waitpid(right, NULL, 0);
-}
-
-int runAndOrCmd(Command *cmd) {
-    int status;
-    if (cmd->type == CMD_AND) {
-        if (fork() == 0) {
-            exit(runCmd(cmd->left));
-        } else {
-            waitpid(-1, &status, 0);
-            if (WIFEXITED(status) && WEXITSTATUS(status) == 0 && fork() == 0) {
-                status = runCmd(cmd->right);
-            }
-            wait(NULL);
-        }
-    } else if (cmd->type == CMD_OR) {
-        if (fork() == 0) {
-            exit(runCmd(cmd->left));
-        } else {
-            waitpid(-1, &status, 0);
-            if (WIFEXITED(status) && WEXITSTATUS(status) != 0 && fork() == 0) {
-                status = runCmd(cmd->right);
-            }
-            wait(NULL);
-        }
-    }
-}
-
-void redirect(Command *cur) {
-    int fd;
-    char *rfile;
-    for (int i = 0; i < 3; i++) {
-        fd = cur->redirectFD[i];
-        rfile = cur->redirectFile[i];
-        if (fd < -1 || fd > 2) {
-            fprintf(stderr, "file descriptor %d is invalid\n", fd);
-            exit(1);
-        }
-        if (fd == i && rfile == NULL) {
-            continue;
-        }
-        if (fd == -1) {
-            // append
-            fd = open(rfile, O_WRONLY | O_CREAT | O_APPEND, 0666);
-        } else if (rfile != NULL) {
-            // normal redirection
-            fd = open(rfile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-        } else {
-            // file descriptor redirection
-            // when here, fd is surely in 0, 1, 2
-            ;
-        }
-
-        if (fd < 0) {
-            fprintf(stderr, "open file %s failed\n", rfile);
-            exit(1);
-        }
-        close(i);
-        dup2(fd, i);
-        close(fd);
+        printf("\033[01;32m%s"
+               "\033[35m@%s\033[00m:"
+               "\033[33m%s\033[00m$ ",
+               username, hostname, pwd);
     }
+    fflush(stdout);
 }
 
-void freeCmd(Command *cmd) {
-    if (cmd == NULL) {
-        return;
-    }
-    if (cmd->left != NULL) {
-        freeCmd(cmd->left);
-    }
-    if (cmd->right != NULL) {
-        freeCmd(cmd->right);
-    }
-    int i;
-    for (i = 0; i < cmd->argc; i++) {
-        free(cmd->args[i]);
+void argInsert(struct Command *cmd, char *s, bool isStr) {
+    if (cmd->argc == 0) {
+        cmd->args = malloc(2 * sizeof(char *));
+    } else {
+        cmd->args = realloc(cmd->args, (cmd->argc + 2) * sizeof(char *));
     }
-    free(cmd->args);
-    for (i = 0; i < 3; i++) {
-        if (cmd->redirectFile[i] != NULL) {
-            free(cmd->redirectFile[i]);
-        }
+    if (isStr) {
+        cmd->args[cmd->argc] = strdup(s + 1);
+        cmd->args[cmd->argc][strlen(cmd->args[cmd->argc]) - 1] = '\0';
+        free(s);
+    } else {
+        cmd->args[cmd->argc] = s;
     }
-    free(cmd);
+    cmd->args[cmd->argc + 1] = NULL;
+    cmd->argc++;
 }
\ No newline at end of file
diff --git a/cmd.c b/cmd.c
new file mode 100644
index 0000000..e38da41
--- /dev/null
+++ b/cmd.c
@@ -0,0 +1,195 @@
+#include "cmd.h"
+
+Command *newCmd() {
+    Command *cmd = (Command *)malloc(sizeof(Command));
+    cmd->argc = 0;
+    cmd->args = NULL;
+    cmd->type = CMD_NORMAL;
+    cmd->left = NULL;
+    cmd->right = NULL;
+    for (int i = 0; i < 3; i++) {
+        cmd->redirectFile[i] = NULL;
+        cmd->redirectFD[i] = i;
+    }
+    cmd->background = false;
+    return cmd;
+}
+
+void freeCmd(Command *cmd) {
+    if (cmd == NULL) {
+        return;
+    }
+    if (cmd->left != NULL) {
+        freeCmd(cmd->left);
+    }
+    if (cmd->right != NULL) {
+        freeCmd(cmd->right);
+    }
+    int i;
+    for (i = 0; i < cmd->argc; i++) {
+        free(cmd->args[i]);
+    }
+    free(cmd->args);
+    for (i = 0; i < 3; i++) {
+        if (cmd->redirectFile[i] != NULL) {
+            free(cmd->redirectFile[i]);
+        }
+    }
+    free(cmd);
+}
+
+int runCmd(Command *cmd) {
+    int status;
+    if (cmd == NULL) {
+        fprintf(stderr, "cmd is NULL\n");
+        return -1;
+    }
+    switch (cmd->type) {
+    case CMD_NORMAL:
+        status = runNormalCmd(cmd);
+        break;
+    case CMD_PIPE:
+        status = runPipeCmd(cmd);
+        break;
+    case CMD_AND:
+    case CMD_OR:
+        status = runAndOrCmd(cmd);
+        break;
+    }
+
+    freeCmd(cmd);
+    return status;
+}
+
+int runNormalCmd(Command *cmd) {
+    pid_t pid;
+    int status;
+    if (!strcmp(cmd->args[0], "exit")) {
+        printf("Good Bye, %s!\n", username);
+        exit(0);
+    } else if (!strcmp(cmd->args[0], "cd")) {
+        if (cmd->argc == 1) {
+            chdir(getenv("HOME"));
+        } else {
+            chdir(cmd->args[1]);
+        }
+        printf("\r");
+        getcwd(pwd, sizeof(pwd));
+    } else {
+        if ((pid = fork()) == 0) {
+            // consider the redirection now
+            // it's just a part of normal command
+            // but not in other commands
+            redirect(cmd);
+            exit(execvp(cmd->args[0], cmd->args));
+        } else {
+            if (!cmd->background) {
+                waitpid(pid, &status, 0);
+                if (!WIFEXITED(status)) {
+                    if (WIFSIGNALED(status)) {
+                        fprintf(stderr, "Process %d was killed by signal %d\n",
+                                pid, WTERMSIG(status));
+                    } else {
+                        fprintf(stderr, "Process %d exited with status %d\n",
+                                pid, WEXITSTATUS(status));
+                    }
+                }
+            }
+        }
+        // return the exit status of the child process
+        return WEXITSTATUS(status);
+    }
+}
+
+int runPipeCmd(Command *cmd) {
+    int status;
+    // create a pipe file and gets two file descriptors
+    // fd[0] is the read end, while fd[1] the write end
+    int fd[2];
+    pid_t left, right;
+    pipe(fd);
+    if ((left = fork()) == 0) {
+        /*
+         * close the read end of the pipe, so that the child process
+         * can only write to it; then redirect the standard output
+         * to the write end of the pipe, and close the write end
+         * itself as a file descriptor.
+         */
+        close(fd[0]);
+        dup2(fd[1], 1);
+        close(fd[1]);
+        exit(runCmd(cmd->left));
+    }
+    if ((right = fork()) == 0) {
+        close(fd[1]);
+        dup2(fd[0], 0);
+        close(fd[0]);
+        exit(runCmd(cmd->right));
+    }
+    // close the pipe, because the parent process doesn't need it
+    // and wait for the two child processes to exit
+    close(fd[0]);
+    close(fd[1]);
+    waitpid(left, NULL, 0);
+    waitpid(right, NULL, 0);
+}
+
+int runAndOrCmd(Command *cmd) {
+    int status;
+    if (cmd->type == CMD_AND) {
+        if (fork() == 0) {
+            exit(runCmd(cmd->left));
+        } else {
+            waitpid(-1, &status, 0);
+            if (WIFEXITED(status) && WEXITSTATUS(status) == 0 && fork() == 0) {
+                status = runCmd(cmd->right);
+            }
+            wait(NULL);
+        }
+    } else if (cmd->type == CMD_OR) {
+        if (fork() == 0) {
+            exit(runCmd(cmd->left));
+        } else {
+            waitpid(-1, &status, 0);
+            if (WIFEXITED(status) && WEXITSTATUS(status) != 0 && fork() == 0) {
+                status = runCmd(cmd->right);
+            }
+            wait(NULL);
+        }
+    }
+}
+
+void redirect(Command *cur) {
+    int fd;
+    char *rfile;
+    for (int i = 0; i < 3; i++) {
+        fd = cur->redirectFD[i];
+        rfile = cur->redirectFile[i];
+        if (fd < -1 || fd > 2) {
+            fprintf(stderr, "file descriptor %d is invalid\n", fd);
+            exit(1);
+        }
+        if (fd == i && rfile == NULL) {
+            continue;
+        }
+        if (fd == -1) {
+            // append
+            fd = open(rfile, O_WRONLY | O_CREAT | O_APPEND, 0666);
+        } else if (rfile != NULL) {
+            // normal redirection
+            fd = open(rfile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+        } else {
+            // file descriptor redirection
+            // when here, fd is surely in 0, 1, 2
+            ;
+        }
+
+        if (fd < 0) {
+            fprintf(stderr, "open file %s failed\n", rfile);
+            exit(1);
+        }
+        close(i);
+        dup2(fd, i);
+        close(fd);
+    }
+}
\ No newline at end of file
diff --git a/cmd.h b/cmd.h
index ce1d44c..7364936 100644
--- a/cmd.h
+++ b/cmd.h
@@ -30,16 +30,19 @@ typedef struct Command {
     bool background;
 } Command;
 
+extern char hostname[100];
+extern char *username;
+extern char pwd[100];
+
 void showPrompt();
-Command *newCmd();
+void argInsert(struct Command *cmd, char *s, bool isStr);
 
+Command *newCmd();
+void freeCmd(Command *cmd);
 int runCmd(Command *cmd);
 int runNormalCmd(Command *cmd);
 int runPipeCmd(Command *cmd);
 int runAndOrCmd(Command *cmd);
-
-void freeCmd(Command *cmd);
-
 void redirect(Command *cur);
 
 #endif
\ No newline at end of file
diff --git a/lex.l b/lex.l
index 4f1497a..73883f6 100644
--- a/lex.l
+++ b/lex.l
@@ -19,6 +19,7 @@ void yyerror(const char *s);
 ">>"                   { return APPEND; }
 "&"                    { return BACKGROUND; }
 [0-2]">"&[0-2]         { yylval.str = strdup(yytext); return FD_REDIRECT; }
+\"[^\"]*\"             { yylval.str = strdup(yytext); return STRING; }
 [a-zA-Z0-9_\-\/\*.]+   { yylval.str = strdup(yytext); return WORD; }
 "("                    { return LPAREN; }
 ")"                    { return RPAREN; }
diff --git a/ohoshell.sh b/ohoshell.sh
index 341b5ad..f45f584 100644
--- a/ohoshell.sh
+++ b/ohoshell.sh
@@ -36,7 +36,7 @@ esac
 flex -o lex.yy.c lex.l
 bison -o syntax.tab.c -d -v syntax.y -Wcounterexamples
 
-$compiler -o bcsh bcsh.c syntax.tab.c -Wall \
+$compiler -o bcsh bcsh.c cmd.c syntax.tab.c -Wall \
         --target=$targetPlatform \
         --sysroot=$native/sysroot \
         -march=$arch -mfloat-abi=softfp
\ No newline at end of file
diff --git a/syntax.y b/syntax.y
index a53537a..7f6745e 100644
--- a/syntax.y
+++ b/syntax.y
@@ -2,6 +2,7 @@
 #include "cmd.h"
 #include "lex.yy.c"
 #include <stdio.h>
+
 %}
 
 %union {
@@ -65,16 +66,19 @@ separator:
 part:
     part WORD {
         $$ = $1;
-        $$->argc++;
-        $$->args = realloc($$->args, ($$->argc + 1) * sizeof(char *));
-        $$->args[$$->argc - 1] = $2;
-        $$->args[$$->argc] = NULL;
+        argInsert($$, $2, false);
     }
     | WORD {
         $$ = newCmd();
-        $$->args = malloc(2 * sizeof(char *));
-        $$->args[$$->argc++] = $1;
-        $$->args[$$->argc] = NULL;
+        argInsert($$, $1, false);
+    }
+    | part STRING {
+        $$ = $1;
+        argInsert($$, $2, true);
+    }
+    | STRING {
+        $$ = newCmd();
+        argInsert($$, $1, true);
     }
     | part REDIRECT_IN WORD {
         $$ = $1;
@@ -99,4 +103,4 @@ part:
     }
     ;
 
-%%
+%%
\ No newline at end of file