Move C code to bin, Makefile, AGPL

1 files changed, 129 insertions, 0 deletions

diff --git a/bin/xx.c b/bin/xx.c
new file mode 100644
index 00000000..e1e31e4a
--- /dev/null
+++ b/bin/xx.c
@@ -0,0 +1,129 @@
+/* Hexdump.
+ *
+ * Copyright (c) 2017, June McEnroe <programble@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ctype.h>
+#include <err.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+static bool allZero(const uint8_t *buf, size_t len) {
+    for (size_t i = 0; i < len; ++i)
+        if (buf[i]) return false;
+    return true;
+}
+
+enum {
+    FLAG_ASCII  = 1 << 0,
+    FLAG_OFFSET = 1 << 1,
+    FLAG_SKIP   = 1 << 2,
+    FLAG_UNDUMP = 1 << 3,
+};
+
+static void dump(size_t cols, size_t group, uint8_t flags, FILE *file) {
+    uint8_t buf[cols];
+    size_t offset = 0, len = 0;
+    for (;;) {
+        offset += len;
+        len = fread(buf, 1, sizeof(buf), file);
+        if (!len) break;
+
+        if ((flags & FLAG_SKIP) && len == sizeof(buf)) {
+            static bool skip;
+            if (allZero(buf, len)) {
+                if (!skip) printf("*\n");
+                skip = true;
+                continue;
+            }
+            skip = false;
+        }
+
+        if (flags & FLAG_OFFSET) {
+            printf("%08zx:  ", offset);
+        }
+
+        for (size_t i = 0; i < len; ++i) {
+            if (group && i && !(i % group)) printf(" ");
+            printf("%02x ", buf[i]);
+        }
+
+        if (flags & FLAG_ASCII) {
+            for (size_t i = len; i < cols; ++i) {
+                printf((group && !(i % group)) ? "    " : "   ");
+            }
+            printf(" ");
+            for (size_t i = 0; i < len; ++i) {
+                if (group && i && !(i % group)) printf(" ");
+                printf("%c", isprint(buf[i]) ? buf[i] : '.');
+            }
+        }
+
+        printf("\n");
+        if (len < sizeof(buf)) break;
+    }
+}
+
+static void undump(FILE *file) {
+    uint8_t byte;
+    int match;
+    while (1 == (match = fscanf(file, " %hhx", &byte))) {
+        printf("%c", byte);
+    }
+    if (match == 0) errx(EX_DATAERR, "invalid input");
+}
+
+int main(int argc, char *argv[]) {
+    size_t cols = 16;
+    size_t group = 8;
+    uint8_t flags = FLAG_ASCII | FLAG_OFFSET;
+    char *path = NULL;
+
+    int opt;
+    while (0 < (opt = getopt(argc, argv, "ac:fg:hku"))) {
+        switch (opt) {
+            case 'a': flags ^= FLAG_ASCII; break;
+            case 'f': flags ^= FLAG_OFFSET; break;
+            case 'k': flags ^= FLAG_SKIP; break;
+            case 'u': flags ^= FLAG_UNDUMP; break;
+            case 'c': cols = strtoul(optarg, NULL, 10); break;
+            case 'g': group = strtoul(optarg, NULL, 10); break;
+            default:
+                fprintf(stderr, "usage: xx [-afku] [-c cols] [-g group] [file]\n");
+                return (opt == 'h') ? EX_OK : EX_USAGE;
+        }
+    }
+    if (!cols) return EX_USAGE;
+    if (argc > optind) {
+        path = argv[optind];
+    }
+
+    FILE *file = path ? fopen(path, "r") : stdin;
+    if (!file) err(EX_NOINPUT, "%s", path);
+
+    if (flags & FLAG_UNDUMP) {
+        undump(file);
+    } else {
+        dump(cols, group, flags, file);
+    }
+
+    if (ferror(file)) err(EX_IOERR, "%s", path);
+    return EX_OK;
+}