`chroot`/Makefile: add chroot

Makefile

@@ -10,7 +10,7 @@ CC_FLAGS :=
 endif
 CC_FLAGS := -Ilib ${CC_FLAGS} 
 ifndef PROGS
-PROGS := arch basename cat cp ls pwd rm uname whoami yes
+PROGS := arch basename cat chroot cp ls pwd rm uname whoami yes
 endif
 ifndef EXCLUDE_PROGS
 EXCLUDE_PROGS := rm

src/chroot.c

@@ -0,0 +1,93 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+/*
+BSD 3-Clause License
+
+Copyright (c) 2021, Ruthenic
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/*
+chroot - changes root directory for a specified process
+available arguments:
+    --help - prints this help message
+    --version - prints version information
+    -c <executable> - runs the specified executable in the new root directory
+instead of the default
+
+usage:
+    chroot [OPTIONS] [DIRECTORY]
+*/
+int runChroot(char *executable, char *directory) {
+  if (chdir(directory) == -1) {
+    perror("chdir");
+    return 1;
+  } else if (chroot(".") == -1) {
+    perror("chroot");
+    return 1;
+  } else if (execvp(executable, NULL) == -1) {
+    perror("execvp");
+    return 1;
+  }
+  return 0;
+}
+
+int main(int argc, char *argv[]) {
+  int i;
+  char *executable = "/bin/sh";
+  char *directory = argv[argc - 1];
+  for (i = 1; i < argc; i++) {
+    if (strcmp(argv[i], "--help") == 0) {
+      printf("chroot - changes root directory for a specified process\n");
+      printf("available arguments:\n");
+      printf("    --help - prints this help message\n");
+      printf("    --version - prints version information\n");
+      printf("    -c <executable> - runs the specified executable in the new "
+             "root directory instead of '/bin/sh'\n");
+      printf("instead of the default\n");
+      printf("usage:\n");
+      printf("    chroot [OPTIONS] [DIRECTORY]\n");
+      return 0;
+    } else if (strcmp(argv[i], "--version") == 0) {
+      printf("%s\n", DRAKECU_VERSION);
+      return 0;
+    } else if (strcmp(argv[i], "-c") == 0) {
+      if (i + 1 < argc) {
+        executable = argv[++i];
+      } else {
+        printf("chroot: option requires an argument -- '-c'\n");
+        return 1;
+      }
+    }
+  }
+  return runChroot(executable, directory);
+}

src/ls.c

@@ -122,11 +122,11 @@ static int listDirs(char *thatpath, bool specpath, bool colour, bool showdot,
         printf("%s  ", words[i]);
         printf(ANSI_RESET);
       } else if (isExecutable(wd) == true) {
-      	printf(ANSI_GREEN);
-      	printf(ANSI_BOLD);
-      	printf("%s  ", words[i]);
-      	printf(ANSI_RESET);
-      	printf(ANSI_RESET);
+        printf(ANSI_GREEN);
+        printf(ANSI_BOLD);
+        printf("%s  ", words[i]);
+        printf(ANSI_RESET);
+        printf(ANSI_RESET);
       } else {
         printf("%s  ", words[i]);
       }