brun

brun (batch-run) is a utility used to run parameterized shell commands

Install

You can install brun using pip:

pip3 install brun

Usage

The simplest brun command looks like the following

brun -f x:range:10 -- echo {x}

If we run this command, the output will be

0
1
2
3
4
5
6
7
8
9

Syntax

The syntax for brun is very simple:

brun --field name:type:arguments -- command

The argument --field (in short -f) defines a field. A field has a name, a type and some arguments. For example, -f x:range:10 defines the field x as the range [0,9]. The delimiter -- indicates where the command begins. The command is a prototype of a shell command with some dynamic parts. For example, echo {x} together with the range x = [0,9] generates 10 commands by replacing {x} with all the values of x.

Fields

brun supports multiple field types.

List

Populates a placeholder according to a list of given values. The syntax is

-f name:list:value1,value2,...

For example, -f x:list:0,2,4, or, similarly -f x:l:0,2,4.

Range

Populates a placeholder according to a given range of values. The syntax is

-f name:range:s[,f[,i]]

If only s is given, the computed range will be [0,s-1]. If only s and f are given, the computed range will be [s,f-1]. If all the three arguments are given, the range will be [s,f-1] with a step of i. The type r is an alias for range.

File

Populates a placeholder according to the content of a file. The syntax is

-f name:file:filepath

The values will be loaded from the given file, the content of one line will generate one value. The type f is an alias for file.

Glob

Populates a placeholder according to the content of a directory. The syntax is

-f name:glob:path,[query,[filter-type]]

The argument path specifies the path to examine, query is a glob-like regular expression to filter the results, filter-type is one of [*, f, g] indicating the types of objects to include, * (all), f (file), d (directories). The type g is an alias for glob.

Groups

Groups are used to link two or more fields together. In particular, a group defines how the values of two or more fields change with respect to each other.

Groups are specified using the argument --group (in short -g). The syntax is the following:

--group type:field1,field2,...[:arguments]

A group has a type, a list of fields (i.e., field1,field2,...), and some arguments.

Cross

The type cross links two or more field values using the Cartesian product. This is the default grouping strategy for fields in brun. For example, the command

brun -f x:r:2 -f y:r:3 -g cross:x,y -- echo {x},{y}

will produce the following output

0,0
0,1
0,2
1,0
1,1
1,2

Zip

The type zip links two or more field values using the indices of their values. Field values will be clipped at the size of the smallest field within the group. For example, the command

brun -f x:r:2 -f y:r:3 -g zip:x,y -- echo {x},{y}

will produce the following output

0,0
1,1