dd

commit 353b5c2d6d9aef05e311074b2942f45f0d598978
Author: ssnf <ssnf@ssnf.xyz>
Date:   Sun, 11 Jul 2021 11:37:17 +0000

inital commit

Diffstat:
A
dd.c
 | 
71
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 71 insertions(+), 0 deletions(-)
diff --git a/dd.c b/dd.c
@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef unsigned char uchar;
+typedef unsigned int uint;
+
+FILE*
+efopen(char* path, char* mode)
+{
+	FILE* f;
+
+	f = fopen(path, mode);
+	if (!f) {
+		perror(path);
+		exit(1);
+	}
+	return f;
+}
+
+int
+main(int argc, char* argv[])
+{
+	FILE* in, *out;
+	char* buf;
+	uint bs, count, i, n;
+
+	in = out = NULL;
+	buf = NULL;
+	bs = 512;
+	count = 0;
+	for (i = 1; i < argc; ++i) {
+		if (!strncmp(argv[i], "if=", 3))
+			in = efopen(argv[i] + 3, "r");
+		else if (!strncmp(argv[i], "of=", 3))
+			out = efopen(argv[i] + 3, "w");
+		else if (!strncmp(argv[i], "count=", 6))
+			sscanf(argv[i] + 6, "%d", &count);
+		else if (!strncmp(argv[i], "bs=", 3)) {
+			sscanf(argv[i] + 3, "%d", &bs);
+			switch (*(argv[i] + strlen(argv[i]) - 1)) {
+				case 'k':
+					bs <<= 10;
+					break;
+				case 'M':
+					bs <<= 20;
+					break;
+				case 'G':
+					bs <<= 30;
+			}
+		}
+	}
+	buf = malloc(bs);
+	if (!in)
+		in = stdin;
+	if (!out)
+		out = stdout;
+	if (count)
+		goto count;
+	while (n = fread(buf, 1, bs, in))
+		fwrite(buf, 1, n, out);
+	goto exit;
+count:
+	for (i = 0; i < count; ++i) {
+		n = fread(buf, 1, bs, in);
+		fwrite(buf, 1, n, out);
+	}
+exit:
+	fclose(in);
+	fclose(out);
+}