1 files changed, 97 insertions, 0 deletions
diff --git a/src/rn.c b/src/rn.c
new file mode 100644
index 0000000..11c8b45
--- /dev/null
+++ b/src/rn.c
@@ -0,0 +1,97 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "util/versie.h"
+#include "io/lines.h"
+
+static void usage(FILE *f) {
+  fprintf(f,
+      "Gebruik: rn [-hV] [BESTAND]...\n"
+      "\n"
+      "Nummereer elke regel van elk BESTAND.\n"
+      "Als geen bestanden gegeven zijn, of het bestand is -, nummereer dan standaard invoer.\n"
+      "\n"
+      "  -p    Regelnummers per BESTAND.\n"
+      "  -h    Toon deze hulptekst\n"
+      "  -V    Toon versienummer\n");
+}
+
+// Returns pointer to argument array containing the file names
+static char** parse_options(int argc, char **argv, bool *perFile) {
+  int opt;
+  while ((opt = getopt(argc, argv, "phV")) != -1) {
+    switch (opt) {
+      case 'p':
+        *perFile = true;
+        break;
+
+      case 'h':
+        usage(stdout);
+        exit(0);
+
+      case 'V':
+        drukkedoos_print_versie(stdout);
+        exit(0);
+
+      case '?':
+        usage(stderr);
+        exit(1);
+    }
+  }
+
+  return argv + optind;
+}
+
+static void process(const char *fname, FILE *file, bool perFile, size_t *n) {
+  if (perFile) *n = 1;
+
+  struct file_lines fl;
+  if (!file_lines_open("rn", fname, file, &fl)) exit(1);
+
+  while (true) {
+    struct string_view sv;
+    if (!file_lines_read(&fl, &sv)) break;
+
+    printf("%6lu  ", *n);
+    fwrite(sv.s, 1, sv.len, stdout);
+    printf("\n");
+
+    *n += 1;
+  }
+
+  file_lines_close(&fl);
+}
+
+int entry_rn(int argc, char **argv) {
+  bool perFile = false;
+  char **args = parse_options(argc, argv, &perFile);
+
+  size_t n = 1;
+
+  if (*args == NULL) {
+    process("stdin", stdin, perFile, &n);
+    return 0;
+  }
+
+  while (*args != NULL) {
+    if (!strcmp(*args, "-")) {
+      process("stdin", stdin, perFile, &n);
+    } else {
+      FILE *file = fopen(*args, "r");
+      if (file == NULL) {
+        fprintf(stderr, "rn: %s: kon bestand niet openen\n", *args);
+        return 1;
+      }
+
+      process(*args, file, perFile, &n);
+      fclose(file);
+    }
+
+    args++;
+  }
+
+  return 0;
+}