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@ -1,13 +1,27 @@
# format
format greps lines from stdin, parses them via regex and reformats them according to a given format string
## Source code
## Input pattern
You can find the source code here: https://git.tordarus.net/Tordarus/format
## Installation
If you have Go installed, you can simply go install the program: `go install git.tordarus.net/Tordarus/format@latest`
There are pre-compiled executables for various platforms on the [repository](https://git.tordarus.net/Tordarus/format/releases).
## License
Distributed under the MIT License. See [LICENSE.md](https://git.tordarus.net/Tordarus/format/src/branch/main/LICENSE.md)
## Usage
### Input pattern
The input pattern describes the format in which the lines are parsed from stdin.
This pattern is a regular expression according to [Go's regexp spec](https://pkg.go.dev/regexp).
Be default, the input pattern will only be applied to every single line.
By default, the input pattern will only be applied to every single line.
When using multiline patterns, you can provide an amount of lines using the command line argument `-n` followed by an integer amount of lines.
Use subgroups for extracting specific parts of the input line.
@ -16,13 +30,15 @@ Provide your custom input pattern with the command line argument `-i '<pattern>'
The default value is `^.*?$` which simply matches the whole line.
## Output pattern
### Output pattern
The output pattern describes the format in which lines are generated for stdout using data from the input pattern.
Provide an output pattern via `-o '<pattern>'`.
The default value is `{0}` which always matches the full input pattern
### Capturing groups
#### Capturing groups
Use the `{<group_index>}` syntax to use a specific capturing group.
- `{0}` always matches the whole line.
@ -30,7 +46,7 @@ Use the `{<group_index>}` syntax to use a specific capturing group.
- `{2}` matches the second capturing group
- and so on
### Formatting
#### Formatting
When referencing capturing groups, you can add a specific format for some data types as well using a simplified printf syntax.
@ -41,7 +57,7 @@ See a full list of formatting options at [Go's fmt spec](https://pkg.go.dev/fmt)
Currently only `%s`, `%d`, `%f` and `%g` are supported though.
### Mutators
#### Mutators
Mutators are a simple way of manipulating number values like integers and floats using a simple math-like expression
@ -57,11 +73,11 @@ The following operators are supported for `%d`, `%f` and `%g` formats:
It is possible to add multiple mutators by just concatenating them: `{1:%d:*2+1}`.
Multiple mutators will not follow any order of operations. They are simply applied from left to right!
**Multiple mutators will not follow any order of operations. They are simply applied from left to right!**
Furthermore you can reference caputring groups which will be parsed as the same type to apply its value. This is done via the following syntax: `{1:%d:+(2)}`. It will parse the first and second capturing group into integers and adds them.
## Handling unmatched lines
### Handling unmatched lines
By default, lines which do not match the input pattern will be dropped.
Use `-k` to keep them unchanged. They will be copied into stdout.
@ -69,8 +85,10 @@ Use `-k` to keep them unchanged. They will be copied into stdout.
## Examples
### Copying
Copying is the default behavior of `format`
Input:
```
```txt
1
2
3
@ -83,7 +101,7 @@ format
```
Output:
```
```txt
1
2
3
@ -95,7 +113,7 @@ Output:
Only keep lines which contains an `i`
Input:
```
```txt
one
two
three
@ -114,7 +132,7 @@ format -i '.*i.*'
```
Output:
```
```txt
five
six
eight
@ -123,9 +141,10 @@ nine
### Removing leading zeros
Use printf syntax on a capturing group in the output pattern
Input:
```
```txt
001
002
003
@ -138,7 +157,7 @@ format -i '\d+' -o '{0:%d}'
```
Output:
```
```txt
1
2
3
@ -148,7 +167,7 @@ Output:
### Extracting dates
Input:
```
```txt
2022-04-18
1970-01-01
2006-01-02
@ -160,18 +179,17 @@ format -i '(\d{4})-(\d{2})-(\d{2})' -o 'day: {3:%d} | month: {2:%d} | year: {1}'
```
Output:
```
```txt
day: 18 | month: 4 | year: 2022
day: 1 | month: 1 | year: 1970
day: 2 | month: 1 | year: 2006
```
### Applying multiple formats
Every format process can only apply a single pattern. Use `-k` to keep unmatched lines so the next format instance can apply another input pattern to them
Every `format` process can only apply a single pattern. Use `-k` to keep unmatched lines so the next `format` instance can apply another input pattern to them
Input:
```
```txt
2022-04-18
1970-01-01
02.01.2006
@ -180,11 +198,12 @@ Input:
Command:
```sh
format -i '(\d{4})-(\d{2})-(\d{2})' -o 'day: {3:%d} | month: {2:%d} | year: {1}' -k | format -i '(\d{2})\.(\d{2})\.(\d{4})' -o 'day: {1:%d} | month: {2:%d} | year: {3}' -k
format -i '(\d{4})-(\d{2})-(\d{2})' -o 'day: {3:%d} | month: {2:%d} | year: {1}' -k |
format -i '(\d{2})\.(\d{2})\.(\d{4})' -o 'day: {1:%d} | month: {2:%d} | year: {3}' -k
```
Output:
```
```txt
day: 18 | month: 4 | year: 2022
day: 1 | month: 1 | year: 1970
day: 2 | month: 1 | year: 2006
@ -192,9 +211,10 @@ day: 2 | month: 2 | year: 1962
```
### Parsing multi-line patterns
Use `-n` to change the amount of lines fed into the input pattern
Input:
```
```txt
year: 2022
month: 04
day: 18
@ -215,7 +235,7 @@ format -n 3 -i '^year: (\d{4})\nmonth: (\d{2})\nday: (\d{2})$' -o 'day: {3:%d} |
```
Output:
```
```txt
day: 18 | month: 4 | year: 2022
day: 1 | month: 1 | year: 1970
day: 2 | month: 1 | year: 2006
@ -223,9 +243,10 @@ day: 2 | month: 2 | year: 1962
```
### Adding 2 values together
Use mutators to apply simple arithmetic on
Input:
```
```txt
5 7
3 2
10 152
@ -238,7 +259,7 @@ format -i '(-?\d+) (-?\d+(?:.\d+)?)' -o '{1} + {2} = {1:%g:+(2)}'
```
Output:
```
```txt
5 + 7 = 12
3 + 2 = 5
10 + 152 = 162
@ -247,10 +268,10 @@ Output:
### Bulk renaming files
Rename a bunch of files at once using format
Rename a bunch of files at once using `format`
Output of `ls`:
```
```txt
000.jpg
001.jpg
002.jpg
@ -262,7 +283,7 @@ ls | format -i '(\d+)\.jpg' -o 'mv "{0}" "{1:%d:+1}.jpg"' | xargs -0 sh -c
```
Output of `ls` afterwards:
```
```txt
1.jpg
2.jpg
3.jpg
@ -291,7 +312,7 @@ There are a few things to consider using this script:
Example usage of this script:
Output of `ls`:
```
```txt
000.jpg
001.jpg
002.jpg
@ -303,7 +324,7 @@ bulkrename '(\d+)\.jpg' '{1:%d:+1}.jpg'
```
Output:
```
```txt
mv "000.jpg" "1.jpg"
mv "001.jpg" "2.jpg"
mv "002.jpg" "3.jpg"
@ -317,7 +338,7 @@ bulkrename '(\d+)\.jpg' '{1:%d:+1}.jpg' exec
```
Output of `ls` afterwards:
```
```txt
1.jpg
2.jpg
3.jpg