tools

README

TOOLS

• Each tool will have a main(). Build with go build <your_tool>.go utils.go. This will produce <your_tool> binary
• Update Makefile for the new tool:
  • new target for building of new tool. Refer to target unzlib in Makefile
  • update all target
  • update install target
• The main will often take an argument filename to read from. If not specified it will read from stdin. Like sort, cat, etc. Call getArgInputFile() method in utils.go to obtain the File* for this purpose
• Place your methods in utils.go and call the method from main.
• The main will only process the command line and call another function with proper arguments - so that the function can also be called from other functions. See unzlib.go as an example
• When adding/modifying code in utils.go demarcate the section you are modifying/adding with a marker to avoid merge conflicts. All your changes should be inside the marked section. E.g.

..some code
/////Changes by <your_name> ////
<Changes by your_name goes here>
func foo() {
}
func xyz() {
}
/////End of changes by <your_name>

//////Changes by <some_other_name> ..
<Changes by some other name goes here>
func newFoo() {
}
//// End of changes by <some_other_name> //

---

unzlib

Decompressed a zlib compressed data.

cat <filename> | unzlib

OR

unzlib <filename>

---

zlib

zlib compress data

Usage

$ cat <filename> | zlib

OR

$ zlib <filename>

---

gensha1

Generates hash of (blob by default)

Usage

$ gensha1 <filename> | echo $(hexdump -ve '1/1 "%.2x"')
$ echo "<contents_of_commit>" | gensha1 -t commit | echo $(hexdump -ve '1/1 "%.2x"')
$ echo "<contents_of_commit>" | gensha1 -t commit | xxd -g0 -ps

Compare with

$ echo 'test content' | git hash-object --stdin

$ echo 'test content' | gensha1 | echo $(hexdump -ve '1/1 "%.2x"')

$ echo -e 'blob 14\0Hello, World!' | shasum

showpackindex

Displays the contents from pack-index file for a given index or an object hash. "-c" option displays the number of objects in the index file

Usage

$ showpackindex -c=true <index-file>
479
$ showpackindex <index-file>
...contents of the index file...

$ showpackindex -h 06041ea2909aadb02891e1d <index_file>

If both -h and -c is provided, -c option will take precedence

Compare with

$ git show-index < <idx_file_name>

showpack

Displays the packed object data for a given pack-file Flags of show pack are:

• -s The offset to read from the pack file (default -1). This flag can be used along with -d or -h.
  • -d Output data for the above object (default true).
  • -h Output header information for the above object
• -v Produce output of git pack-verify -v (default true)

Usage

$ showpackindex -v <pack_file>
590 06041ea2909aadb02891e1d96f2cee00ba7f7d59 (98db6920)
...
$ showpackindex -s 12 <pack_file>
<Contents of object at index 12 in packfile displayed>
...
$ showpackindex -h -s 12 <pack_file>
<Contents of object at index 12 in packfile displayed along with header information>
...

$ showpack -s 12 -h -d=false sample.pack
<Only header information displayed for the object at offset 12>

Compare with

$ git verify-pack -v <pack_file>

lstree

Lists the details of a tree object

Usage

$ cat <filename> | unzlib | lstree

Compare the following:

$ git cat-file -p <hash_of_a_tree>

$ cat `obj2file <hash_of_a_tree>` |  unzlib | lstree

---

lstype

Lists the type object

Usage

$ cat <filename> | unzlib | lstype

Compare the following:

$ git cat-file -t <hash_of_object>

$ $ cat `obj2file <hash_of_object>` |  unzlib | lstype

---

obj2file

Converts a loose object (hash) to file path.

Usage

$ cat `obj2file <hash>`  |unzlib

---

lslobj

Lists all loose objects in a repository.

Usage

$ lslobj -d /path/to/repo

---

initr

Creates an empty [bare] git repository

Usage

$ initr /path/to/repo
$ initr -bare /path/to/repo

---

ppcommit

Pretty print a commit object, reading the decompressed commit object from stdin or file.

Usage

$ cat `obj2file <commit-hash>` | unzlib | ppcommit

lscommits

Lists all commits starting from a given sha

$ lscommits -d path/to/repo/ c3fd86874adcd6a1fad06c049b64026ce14a59e5

repostat

prints stats about repository

$ repostat /path/to/repo

---

pptag

Pretty print an annotated tag object.

$ cat `obj2file <tag-hash>` | unzlib | pptag

---

ppfixtures

Prints test fixtures to stdout.

$ ppfixtures -h
Usage of ppfixtures:
  -c string
    	print fixture for object type. [all|commit|blob|tree|tag] (default "all")
  -s string
    	print fixture of given size. [xs|sm|md|lg|xl] (default "sm")

---

lsrefs

list all references in the local repository. This is equivalent to $ git show-ref

Usage

$ lsrefs -d /path/to/repo

---

TODO

• Change *os.File to io.Reader in the function arguments in utils.go
• tree2fs to convert a tree into a folder structure in the file-system.
• fs2tree convert a folder structure to a tree object
• unpack Unpack objects from a packed archive
• pack Create a packed archive of objects