`rm`/Makefile: add `rm`.

another gamer added to the ranks of the esports team.
supports recursive deletion of directories.

Makefile

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

src/rm.c

@@ -0,0 +1,149 @@
+#include <dirent.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "checks.h"
+#include "file.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.
+*/
+
+int removeFileOrDirectory(char *path, bool recursive, bool force) {
+  if (isDirectory(path)) {
+    if (recursive == true) {
+      DIR *dirp;
+      struct dirent *dp;
+      char *fullname;
+      dirp = opendir(path);
+      do {
+        if ((dp = readdir(dirp)) != NULL) {
+          if (strcmp(dp->d_name, ".") && strcmp(dp->d_name, "..")) {
+            fullname = malloc(strlen(dp->d_name) + strlen(path) + 2);
+            sprintf(fullname, "%s/%s", path, dp->d_name);
+            // printf("%s\n", dp->d_name);
+            if (!isDirectory(fullname)) {
+              unlink(fullname);
+            } else {
+              removeFileOrDirectory(fullname, recursive, force);
+            }
+            free(fullname);
+            if (errno != 0) {
+              if (errno == EACCES || errno == EPERM) {
+                printf("unable to access '%s'. you probably need higher "
+                       "permissions.\n",
+                       path);
+              } else {
+                printf("unknown error occured when trying to remove '%s'.\n",
+                       path);
+              }
+              return errno;
+            }
+          }
+        }
+      } while (dp != NULL);
+      rmdir(path);
+    } else {
+      rmdir(path);
+      if (errno == 0) {
+        return 0;
+      } else if (errno == ENOTEMPTY) {
+        printf("'%s' not empty. try recursive deletion instead.\n", path);
+      } else if (errno == EACCES) {
+        printf("unable to access '%s'. you probably need higher permissions.\n",
+               path);
+      } else {
+        printf("unknown error occured when trying to remove '%s'.\n", path);
+      }
+      return errno;
+    }
+  } else {
+    unlink(path);
+    if (errno == 0) {
+      return 0;
+    } else if (errno == EACCES || errno == EPERM) {
+      printf("unable to access '%s'. you probably need higher permissions.\n",
+             path);
+    } else {
+      printf("unknown error occured when trying to remove '%s'.\n", path);
+    }
+    return errno;
+  }
+}
+
+int main(int argc, char **argv) {
+  bool recursive = false;
+  bool force = false;
+  char *path;
+  for (int i = 1; i < argc; i++) {
+    char *arg = argv[i];
+    /*printf(arg);
+    printf(" ");*/
+    if (!strcmp(arg, "--help")) {
+      char *help =
+          "Drake's Epic Coreutils (working title) " DRAKECU_VERSION "\n"
+          "rm - removes files and directories.\n"
+          "available arguments:\n"
+          "	--help:          show this help message\n"
+          "	--version:       show the version of the program\n"
+          "	--recursive, -r: recursively delete files inside directories.\n"
+          "usage:\n"
+          "	rm -{r} [long options] [file/directory]";
+      printf("%s\n", help);
+      return 0;
+    } else if (!strcmp(arg, "--version")) {
+      printf("%s\n", DRAKECU_VERSION);
+      return 0;
+    } else if (!strcmp(arg, "--recursive")) {
+      recursive = true;
+    } else if (!strcmp(arg, "--force")) {
+      // what does --force/-f *actually* mean? yea, we all use it... but like
+      // why not use `rm -r`
+      // this might just be a placebo/compatibility thing atm, lol
+      force = true;
+    } else if (startsWithChar(arg, '-')) {
+      for (int i = 1; i < (int)strlen(arg); i++) {
+        if (arg[i] == 'r') {
+          recursive = true;
+        } else if (arg[i] == 'f') {
+          force = true;
+        }
+      }
+    } else {
+      removeFileOrDirectory(arg, recursive, force);
+    }
+  }
+}