# Table of contents
- [ppbert](#ppbert)
# ppbert
A command-line utility to pretty print structures encoded using
Erlang's [External Term Format](http://erlang.org/doc/apps/erts/erl_ext_dist.html).
The input is read from *stdin* or a file and written to *stdout*,
making ppbert a good candidate for shell pipelines.
At the moment, ppbert supports the following subset of the External
Term Format:
- Small integers (tag: 97);
- Integers (tag: 98);
- Floating-point numbers (tags: 70, 99);
- Big integers (tags: 110, 111);
- Latin-1 atoms (tags: 100, 115);
- UTF-8 atoms (tags: 118, 119);
- Strings (tag: 107);
- Binaries (tag: 109);
- Tuples (tags: 104, 105);
- Lists (tags: 106, 108);
- Maps (tag: 116).
## Usage
```
$ ppbert --help
ppbert 0.9.0
Options:
-V, --version display version
-h, --help display this help
-i, --indent NUM indent with NUM spaces
-m, --per-line NUM print at most NUM basic terms per line
-p, --parse parse only, not pretty print
-2, --bert2 parse .bert2 files
-d, --disk-log parse disk_log files
-v, --verbose show diagnostics on stderr
-j, --json print as JSON
-t, --transform-proplists
convert proplists to JSON objects
$ ppbert mini_dict.bert
[
{host, "localhost"},
{port, 80},
{
headers,
[
{
<<"X-Real-Ip">>,
{127, 0, 0, 1}
},
{<<"Keep-alive">>, true}
]
}
]
$ printf "\x83\x77\x04atom" | ppbert
atom
```
## Performance
Ppbert is written in Rust and offers an appreciable performance gain
over using Erlang's `erlang:binary_to_term/1` and `io:format/2`.
```sh
$ cat erl_ppbert
#!/usr/bin/env escript
main(Args) ->
lists:foreach(fun (Filename) ->
{ok, Binary} = file:read_file(Filename),
io:format("~p~n", [binary_to_term(Binary)])
end, Args).
$ du large.bert
96M large.bert
$ time ./erl_ppbert large.bert >/dev/null
real 0m43.017s
user 0m38.846s
sys 0m4.345s
$ time ppbert large.bert >/dev/null
real 0m1.802s
user 0m1.251s
sys 0m0.549s
```