Choose
This is choose, a human-friendly and fast alternative to cut and (sometimes) awk
Features
- terse field selection syntax similar to Python's list slices
- negative indexing from end of line
- optional start/end index
- zero-indexed
- reverse ranges
- slightly faster than
cutfor sufficiently long inputs, much faster than
awk - regular expression field separators using Rust's regex syntax
Rationale
The AWK programming language is designed for text processing and is extremely
capable in this endeavor. However, the awk command is not ideal for rapid
shell use, with its requisite quoting of a line wrapped in curly braces, even
for the simplest of programs:
awk '{print $1}'
Likewise, cut is far from ideal for rapid shell use, because of its confusing
syntax. Field separators and ranges are just plain difficult to get right on the
first try.
It is for these reasons that I present to you choose. It is not meant to be a
drop-in or complete replacement for either of the aforementioned tools, but
rather a simple and intuitive tool to reach for when the basics of awk or
cut will do, but the overhead of getting them to behave should not be
necessary.
Contributing
Please see our guidelines in contributing.md.
Usage
$ choose --help
choose 1.2.0
`choose` sections from each line of files
USAGE:
choose [FLAGS] [OPTIONS] <choices>...
FLAGS:
-c, --character-wise Choose fields by character number
-d, --debug Activate debug mode
-x, --exclusive Use exclusive ranges, similar to array indexing in many programming languages
-h, --help Prints help information
-n, --non-greedy Use non-greedy field separators
-V, --version Prints version information
OPTIONS:
-f, --field-separator <field-separator>
Specify field separator other than whitespace, using Rust `regex` syntax
-i, --input <input> Input file
-o, --output-field-separator <output-field-separator> Specify output field separator
ARGS:
<choices>... Fields to print. Either a, a:b, a..b, or a..=b, where a and b are integers. The beginning or end
of a range can be omitted, resulting in including the beginning or end of the line,
respectively. a:b is inclusive of b (unless overridden by -x). a..b is exclusive of b and a..=b
is inclusive of b
Examples
choose 5 # print the 5th item from a line (zero indexed)
choose -f ':' 0 3 5 # print the 0th, 3rd, and 5th item from a line, where
# items are separated by ':' instead of whitespace
choose 2:5 # print everything from the 2nd to 5th item on the line,
# inclusive of the 5th
choose -x 2:5 # print everything from the 2nd to 5th item on the line,
# exclusive of the 5th
choose :3 # print the beginning of the line to the 3rd item
choose -x :3 # print the beginning of the line to the 3rd item,
# exclusive
choose 3: # print the third item to the end of the line
choose -1 # print the last item from a line
choose -3:-1 # print the last three items from a line
Compilation and Installation
Installing From Source
In order to build choose you will need the rust toolchain installed. You can
find instructions here.
Then, to install:
$ git clone https://github.com/theryangeary/choose.git
$ cd choose
$ cargo build --release
$ install target/release/choose <DESTDIR>
Just make sure DESTDIR is in your path.
Installing From Package Managers
Cargo:
$ cargo install choose
Arch Linux:
$ yay -S choose-rust-git
Fedora/CentOS COPR:
$ dnf copr enable atim/choose
$ dnf install choose
Homebrew:
$ brew install choose-rust
Benchmarking
Benchmarking is performed using the bench utility.
Benchmarking is based on the assumption that there are five files in test/
that match the glob "long*txt". GitHub doesn't support files big enough in
normal repos, but for reference the files I'm working with have lengths like
these:
1000 test/long.txt
19272 test/long_long.txt
96360 test/long_long_long.txt
963600 test/long_long_long_long.txt
10599600 test/long_long_long_long_long.txt
and content generally like this:
Those an equal point no years do. Depend warmth fat but her but played. Shy and
subjects wondered trifling pleasant. Prudent cordial comfort do no on colonel as
assured chicken. Smart mrs day which begin. Snug do sold mr it if such.
Terminated uncommonly at at estimating. Man behaviour met moonlight extremity
acuteness direction.
Ignorant branched humanity led now marianne too strongly entrance. Rose to shew
bore no ye of paid rent form. Old design are dinner better nearer silent excuse.
She which are maids boy sense her shade. Considered reasonable we affronting on
expression in. So cordial anxious mr delight. Shot his has must wish from sell