Renaming folders

chp3_process/osh_shell/osh.c

@@ -0,0 +1,147 @@
+#include "history.h"
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+struct command_t {
+  char **args;
+  bool bg_flag;
+};
+
+struct command_t parse_command(char *);
+int digits(char *);
+
+int main(void) {
+
+  // Create and/or read history file
+  int history_count = allocate_history();
+  if (history_count < 0) {
+    perror("Error");
+    exit(EXIT_FAILURE);
+  }
+
+  int should_run = 1;
+  while (should_run) {
+    char raw[MAXLEN / 2 + 1];
+    printf("osh> ");
+    fflush(stdout);
+    fgets(raw, MAXLEN / 2 + 1, stdin);
+
+    // check if user press newline
+    if (strcmp(raw, "\n") == 0) {
+      continue;
+    }
+
+    // FIXME: handle ^D shortcut
+    if (strcmp(raw, "\000") == 0) {
+      exit(EXIT_SUCCESS);
+    }
+
+    char *c;
+    if (strcmp(raw, "!!\n") == 0) {
+      if (nth_command(raw, history_count) != -1) {
+        printf("%s\n", raw);
+      } else {
+        printf("History is empty\n");
+        continue;
+      }
+    } else if ((c = strchr(raw, '!')) != NULL) {
+      const int n = digits(c);
+      if (nth_command(raw, n) != -1) {
+        printf("%s\n", raw);
+      } else {
+        printf("Command not found in position %d\n", n);
+        continue;
+      }
+    }
+
+    // remove carriage return
+    raw[strlen(raw) - 1] = '\0';
+
+    // save command in the history file
+    history_count = add_history(history_count, raw);
+
+    struct command_t cmd = parse_command(raw);
+    if (strcmp(cmd.args[0], "exit") == 0) {
+      should_run = 0;
+    } else if (strcmp(cmd.args[0], "history") == 0) {
+      // print on the stdout last 10 commands in reverse way
+      history_entry_t *history = get_history(history_count);
+      for (int i = HISTORY_SIZE - 1; i >= 0; i--) {
+        history_entry_t entry = history[i];
+        if (entry.line_number != 0) {
+          printf("%5d\t%s", entry.line_number, entry.command);
+        }
+      }
+
+      free(history);
+      history = NULL;
+    } else {
+      pid_t pid = fork();
+      switch (pid) {
+      case -1:
+        perror("Fork\n");
+        exit(EXIT_FAILURE);
+      case 0:
+        should_run = 0;
+        if (execvp(cmd.args[0], cmd.args)) {
+          perror("Error");
+        }
+        break;
+      default:
+        if (!cmd.bg_flag) {
+          wait(NULL);
+        }
+
+        break;
+      }
+    }
+
+    free(cmd.args);
+    cmd.args = NULL;
+  }
+
+  return EXIT_SUCCESS;
+}
+
+struct command_t parse_command(char *raw) {
+  int i = 0;
+  bool bg_flag = false;
+  char **args = (char **)calloc(MAXLEN, sizeof(char *));
+  char *tok = strtok(raw, " ");
+  while (tok != NULL) {
+    if (strcmp(tok, "&") == 0) {
+      bg_flag = true;
+    } else {
+      args[i] = tok;
+    }
+    tok = strtok(NULL, " ");
+    i++;
+  }
+
+  struct command_t cmd = {.args = args, .bg_flag = bg_flag};
+  return cmd;
+}
+
+int digits(char *s) {
+  char *sub = malloc(strlen(s) * sizeof(s));
+  char c;
+  int i = 0, j = 0;
+  while ((c = s[i]) != '\n') {
+    if (isdigit(c)) {
+      sub[j++] = c;
+    }
+    i++;
+  }
+
+  int n = atoi(sub);
+
+  free(sub);
+  sub = NULL;
+
+  return n;
+}