2 files changed, 118 insertions, 0 deletions
diff --git a/usr.bin/cat/Makefile b/usr.bin/cat/Makefile
new file mode 100644
index 0000000..4ecfea7
--- /dev/null
+++ b/usr.bin/cat/Makefile
@@ -0,0 +1,6 @@
+include user.mk
+
+CFILES = $(shell find . -name "*.c")
+
+$(ROOT)/base/usr/bin/cat:
+	gcc $(CFILES) -o $@ $(INTERNAL_CFLAGS)
diff --git a/usr.bin/cat/cat.c b/usr.bin/cat/cat.c
new file mode 100644
index 0000000..4fb74d1
--- /dev/null
+++ b/usr.bin/cat/cat.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * 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 Hyra 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 OWNER 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.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define NUM_MODE_NONE       0
+#define NUM_MODE_ALL        1
+#define NUM_MODE_NONBLANK   2
+
+static void
+help(void)
+{
+    printf(
+        "usage: cat <flags> <file>\n"
+        "[-b]   do not number blank lines\n"
+        "[-n]   number all lines\n"
+    );
+}
+
+static void
+cat(const char *pathname, int num_mode)
+{
+    FILE *file;
+    char buf[64];
+    int fd;
+    size_t lineno = 1;
+
+    file = fopen(pathname, "r");
+    if (file == NULL) {
+        return;
+    }
+
+    while (fgets(buf, sizeof(buf), file) != NULL) {
+        switch (num_mode) {
+        case NUM_MODE_NONE:
+            break;
+        case NUM_MODE_ALL:
+            printf("%d   ", lineno);
+            break;
+        case NUM_MODE_NONBLANK:
+            if (buf[0] == '\n') {
+                break;
+            }
+            printf("%d   ", lineno);
+            break;
+        }
+        printf("%s", buf);
+        ++lineno;
+    }
+
+    fclose(file);
+}
+
+int
+main(int argc, char **argv)
+{
+    int num_mode = NUM_MODE_NONE;
+    int c;
+
+    if (argc < 2) {
+        help();
+        return -1;
+    }
+
+    while ((c = getopt(argc, argv, "nb")) != -1) {
+        switch (c) {
+        case 'n':
+            num_mode = NUM_MODE_ALL;
+            break;
+        case 'b':
+            num_mode = NUM_MODE_NONBLANK;
+            break;
+        }
+    }
+
+    for (size_t i = optind; i < argc; ++i) {
+        cat(argv[i], num_mode);
+    }
+
+    return 0;
+}