first cut; doesn't change formats, cuts off last block

1 files changed, 221 insertions, 0 deletions

diff --git a/od.c b/od.c
new file mode 100644
index 0000000..6fb7e28
--- /dev/null
+++ b/od.c
@@ -0,0 +1,221 @@
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+union block {
+	char c[16];
+	short s[16 / sizeof(short)];
+	unsigned short us[16 / sizeof(unsigned short)];
+	int i[16 / sizeof(int)];
+	unsigned int ui[16 / sizeof(unsigned int)];
+	long l[16 / sizeof(long)];
+	unsigned long ul[16 / sizeof(unsigned long)];
+	long long ll[16 / sizeof(long long)];
+	unsigned long long ull[16 / sizeof(unsigned long long)];
+	float f[16 / sizeof(float)];
+	double d[16 / sizeof(double)];
+	long double ld[16 / sizeof(long double)];
+};
+
+static int escapes = 0;
+static int verbose = 0;
+
+static int addoutput(const char *type)
+{
+	(void)type;
+	return 0;
+}
+
+static int od(const char *filename, char address_base, unsigned long skip, unsigned long skipsize, unsigned long maxbytes)
+{
+	FILE *in = stdin;
+	union block prev;
+	union block b;
+	size_t nread = 0;
+	int star = 0;
+	char basefmt[] = { '%', '0', '7', 'z', address_base, ' ', '\0' };
+
+	if (strcmp(filename, "-")) {
+		in = fopen(filename, "rb");
+		if (in == NULL) {
+			fprintf(stderr, "od: couldn't open %s: %s\n", filename, strerror(errno));
+			return 1;
+		}
+	}
+
+	if (skip > skipsize) {
+		unsigned long tmp = skip;
+		skip = skipsize;
+		skipsize = tmp;
+	}
+
+	for (unsigned long i = 0; i < skip; i++) {
+		fseek(in, skipsize, SEEK_SET);
+		nread += skipsize;
+	}
+
+	while ((fread(&b, sizeof(b), 1, in)) == 1) {
+		nread += sizeof(b);
+		if (maxbytes && nread >= maxbytes) {
+			break;
+		}
+
+		if (!verbose && memcmp(&prev, &b, sizeof(b)) == 0) {
+			if (!star) {
+				printf("*\n");
+				star = 1;
+			}
+			continue;
+		}
+
+		star = 0;
+
+		if (address_base != 'n') {
+			printf(basefmt, nread - sizeof(b));
+		}
+
+		/* TODO: this loop */
+		size_t nloops = sizeof(b.s) / sizeof(b.s[0]);
+		for (size_t i = 0; i < nloops; i++) {
+			printf("%06ho%c", b.s[i], i == nloops - 1 ? '\n' : ' ');
+		}
+
+		memcpy(&prev, &b, sizeof(b));
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	char *endopt = NULL;
+	unsigned long skip = 0;
+	unsigned long maxbytes = 0;
+	unsigned long skipsize = 1;
+	int xsi_offset = 1;
+	char address_base = 'o';
+	int c;
+
+	setlocale(LC_ALL, "");
+
+	while ((c = getopt(argc, argv, "A:bcdj:Nost:vx")) != -1) {
+		switch (c) {
+		case 'A':
+			xsi_offset = 0;
+			if (strlen(optarg) != 1) {
+				return 1;
+			}
+			address_base = *optarg;
+			if (address_base != 'd' && address_base != 'o' && address_base != 'x' && address_base != 'n') {
+				return 1;
+			}
+			break;
+
+		case 'b':
+			addoutput("o1");
+			break;
+
+		case 'c':
+			escapes = 1;
+			break;
+
+		case 'd':
+			addoutput("u2");
+			break;
+
+		case 'j':
+			xsi_offset = 0;
+			skip = strtoul(optarg, &endopt, 0);
+			switch (*endopt) {
+			case 'b':
+				skipsize = 512;
+				break;
+
+			case 'k':
+				skipsize = 1024;
+				break;
+
+			case 'm':
+				skipsize = 1024 * 1024;
+				break;
+
+			case '\0':
+				break;
+
+			default:
+				fprintf(stderr, "od: unknown suffix '%c'\n", *endopt);
+				return 1;
+			}
+			break;
+
+		case 'N':
+			xsi_offset = 0;
+			maxbytes = strtoul(optarg, NULL, 0);
+			break;
+
+		case 'o':
+			addoutput("o2");
+			break;
+
+		case 's':
+			addoutput("d2");
+			break;
+
+		case 't':
+			xsi_offset = 0;
+			if (addoutput(optarg) != 0) {
+				return 1;
+			}
+			break;
+
+		case 'v':
+			xsi_offset = 0;
+			verbose = 1;
+			break;
+
+		case 'x':
+			addoutput("x2");
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (xsi_offset) {
+		/* check argv[argc-1] */
+		char *xo = "";
+		int base = 8;
+		size_t len = strlen(xo);
+
+		/* ignore leading '+' */
+		if (*xo == '+') {
+			xo++;
+			len--;
+		}
+
+		if (len > 1 && xo[len-1] == 'b') {
+			skipsize = 512;
+			xo[len-1] = '\0';
+			len--;
+		}
+
+		if (len > 1 && xo[len-1] == '.') {
+			base = 10;
+			xo[len-1] = '\0';
+		}
+
+		skip = strtoul(argv[argc-1], NULL, base);
+	}
+
+	int ret = 0;
+	do {
+		ret |= od(argv[optind++], address_base, skip, skipsize, maxbytes);
+	} while (argv[optind]);
+
+	return ret;
+}