Initial commit

1 files changed, 106 insertions, 0 deletions

diff --git a/src/hush.c b/src/hush.c
new file mode 100644
index 0000000..478103f
--- /dev/null
+++ b/src/hush.c
@@ -0,0 +1,106 @@
+/*
+ * hush -- the HU Shell
+ *
+ * A minimal shell for CISC 301, Operating Systems
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include "config.h"
+#include "lexer.h"
+#include "command.h"
+
+FILE *open_input(int argc, char **argv) {
+  FILE *input_file = (argc > 1) ? fopen(argv[1], "r") : stdin;
+  if (!input_file) {
+    fprintf(stderr, "ERROR: Failed to open input file %s\n", argv[1]);
+    exit(EXIT_FAILURE);
+  }
+
+  return input_file;
+}
+
+static size_t get_command_len(char *cmdstr) {
+  size_t len = strlen(cmdstr);
+  if (cmdstr[len - 1] != '\n') {
+    len = 0;
+  }
+
+  return len;
+}
+
+int main(int argc, char **argv) {
+  FILE *input_file = open_input(argc, argv);
+  char buffer[MAX_LINE_LEN];
+
+  fprintf(stdout, "$ ");
+  while (fgets(buffer, MAX_LINE_LEN, input_file)) {
+    char *cmdstr = trim(buffer);
+    if (!cmdstr) { 
+      fprintf(stderr, "ERROR: Specified command is too long\n");
+      goto draw_prompt;
+    }
+
+    if (strlen(cmdstr) == 0) {
+      goto draw_prompt;
+    }
+
+    token *parsed_cmd;
+    if (!(parsed_cmd = parse_command(cmdstr))) {
+      fprintf(stderr, "ERROR: Failed to parse command\n");
+      goto draw_prompt;
+    }
+
+    {
+      token *error;
+      if ((error = validate_command(parsed_cmd))) {
+        fprintf(stderr, "ERROR: Invalid syntax near %s\n", error->text);
+        print_parsed_command(stdout, parsed_cmd);
+        goto free_tokens;
+      }
+    }
+
+    // print_parsed_command(stdout, parsed_cmd);
+
+    if (parsed_cmd->type == TKN_VARKEY) {
+      /* handle variable creation */
+      goto free_tokens;
+    }
+
+    size_t commands;
+    command *cmds;
+    if (!(cmds = commands_from_tokens(parsed_cmd, &commands ))) {
+      fprintf(stderr, "ERROR: Unable to create commands from tokens");
+      goto free_tokens;
+    }
+
+    // print_commands(stdout, cmds);
+
+    for (command *cmd = cmds; cmd; cmd = cmd->next) {
+      pid_t result = execute_command(cmd);
+      if (result < 0) {
+        break;
+      }
+    }
+
+    for (command *cmd = cmds; cmd; cmd = cmd->next) {
+      if (cmd->pid > 0) {
+        waitpid(cmd->pid, NULL, 0);
+      }
+    }
+
+  free_tokens:
+    destroy_tokens(parsed_cmd);
+
+  free_commands:
+  destroy_commands(cmds);
+
+  draw_prompt:
+    fprintf(stdout, "$ ");
+  }
+}