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Revision a5bf71be4ada0d8e914c23c2fc334ce1899e36c1 authored by Stefan Beller on 22 May 2015, 19:17:52 UTC, committed by Stefan Beller on 22 May 2015, 19:17:52 UTC 
submodule documentation: Reorder introductory paragraphs
 
It's better to start the man page with a description of what submodules
actually are instead of saying what they are not.

Reorder the paragraphs such that
the first short paragraph introduces the submodule concept,
the second paragraph highlights the usage of the submodule command,
the third paragraph giving background information,
and finally the fourth paragraph discusing alternatives such
as subtrees and remotes, which we don't want to be confused with.

This ordering deepens the knowledge on submodules with each paragraph.
First the basic questions like "How/what" will be answered, while the
underlying concepts will be taught at a later time.

Making sure it is not confused with subtrees and remotes is not really
enhancing knowledge of submodules itself, but rather painting the big
picture of git concepts, so you could also argue to have it as the second
paragraph. Personally I think this may confuse readers, specially
newcomers though.

Additionally to reordering the paragraphs, they have been slightly
reworded.

Signed-off-by: Stefan Beller <sbeller@google.com>
1 parent 6c1249c
Raw File
show-index.c 
#include "cache.h"
#include "pack.h"

static const char show_index_usage[] =
"git show-index < <packed archive index>";

int main(int argc, char **argv)
{
	int i;
	unsigned nr;
	unsigned int version;
	static unsigned int top_index[256];

	git_setup_gettext();

	if (argc != 1)
		usage(show_index_usage);
	if (fread(top_index, 2 * 4, 1, stdin) != 1)
		die("unable to read header");
	if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
		version = ntohl(top_index[1]);
		if (version < 2 || version > 2)
			die("unknown index version");
		if (fread(top_index, 256 * 4, 1, stdin) != 1)
			die("unable to read index");
	} else {
		version = 1;
		if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
			die("unable to read index");
	}
	nr = 0;
	for (i = 0; i < 256; i++) {
		unsigned n = ntohl(top_index[i]);
		if (n < nr)
			die("corrupt index file");
		nr = n;
	}
	if (version == 1) {
		for (i = 0; i < nr; i++) {
			unsigned int offset, entry[6];

			if (fread(entry, 4 + 20, 1, stdin) != 1)
				die("unable to read entry %u/%u", i, nr);
			offset = ntohl(entry[0]);
			printf("%u %s\n", offset, sha1_to_hex((void *)(entry+1)));
		}
	} else {
		unsigned off64_nr = 0;
		struct {
			unsigned char sha1[20];
			uint32_t crc;
			uint32_t off;
		} *entries = xmalloc(nr * sizeof(entries[0]));
		for (i = 0; i < nr; i++)
			if (fread(entries[i].sha1, 20, 1, stdin) != 1)
				die("unable to read sha1 %u/%u", i, nr);
		for (i = 0; i < nr; i++)
			if (fread(&entries[i].crc, 4, 1, stdin) != 1)
				die("unable to read crc %u/%u", i, nr);
		for (i = 0; i < nr; i++)
			if (fread(&entries[i].off, 4, 1, stdin) != 1)
				die("unable to read 32b offset %u/%u", i, nr);
		for (i = 0; i < nr; i++) {
			uint64_t offset;
			uint32_t off = ntohl(entries[i].off);
			if (!(off & 0x80000000)) {
				offset = off;
			} else {
				uint32_t off64[2];
				if ((off & 0x7fffffff) != off64_nr)
					die("inconsistent 64b offset index");
				if (fread(off64, 8, 1, stdin) != 1)
					die("unable to read 64b offset %u", off64_nr);
				offset = (((uint64_t)ntohl(off64[0])) << 32) |
						     ntohl(off64[1]);
				off64_nr++;
			}
			printf("%" PRIuMAX " %s (%08"PRIx32")\n",
			       (uintmax_t) offset,
			       sha1_to_hex(entries[i].sha1),
			       ntohl(entries[i].crc));
		}
		free(entries);
	}
	return 0;
}
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