Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

https://github.com/chmln/sd

Intuitive find & replace CLI (sed alternative)
https://github.com/chmln/sd

cli command-line regex rust terminal text-processing

Last synced: about 1 month ago
JSON representation

Intuitive find & replace CLI (sed alternative)

Lists

README 

        
# sd - `s`earch & `d`isplace



`sd` is an intuitive find & replace CLI.



## The Pitch



Why use it over any existing tools?



*Painless regular expressions.*   `sd` uses regex syntax that you already know from JavaScript and Python. Forget about dealing with quirks of `sed` or `awk` - get productive immediately.



*String-literal mode.*   Non-regex find & replace. No more backslashes or remembering which characters are special and need to be escaped.



*Easy to read, easy to write.*   Find & replace expressions are split up, which makes them easy to read and write. No more messing with unclosed and escaped slashes.



*Smart, common-sense defaults.*   Defaults follow common sense and are tailored for typical daily use.



## Comparison to sed



While sed does a whole lot more, sd focuses on doing just one thing and doing it well. Here are some cherry-picked examples where sd shines.



Simpler syntax for replacing all occurrences:

  - sd: `sd before after`

  - sed: `sed s/before/after/g`



Replace newlines with commas:

  - sd: `sd '\n' ','`

  - sed: `sed ':a;N;$!ba;s/\n/,/g'`



Extracting stuff out of strings containing slashes:

  - sd: `echo "sample with /path/" | sd '.*(/.*/)' '$1'`

  - sed: `echo "sample with /path/" | sed -E 's/.*(\\/.*\\/)/\1/g'`

    

    With sed, you can make it better with a different delimiter,

    but it is still messy:

    

    `echo "sample with /path/" | sed -E 's|.*(/.*/)|\1|g'`



In place modification of files:

  - sd: `sd before after file.txt`

  - sed: `sed -i -e 's/before/after/g' file.txt`

    

    With sed, you need to remember to use `-e` or else some

    platforms will consider the next argument to be a backup suffix.



## Benchmarks



**Simple replacement on ~1.5 gigabytes of JSON**



```sh

hyperfine --warmup 3 --export-markdown out.md \

  'sed -E "s/\"/'"'"'/g" *.json > /dev/null' \

  'sed    "s/\"/'"'"'/g" *.json > /dev/null' \

  'sd     "\"" "'"'"'"   *.json > /dev/null'

```



| Command | Mean [s] | Min…Max [s] |

|:---|---:|---:|

| `sed -E "s/\"/'/g" *.json > /dev/null` | 2.338 ± 0.008 | 2.332…2.358 |

| `sed    "s/\"/'/g" *.json > /dev/null` | 2.365 ± 0.009 | 2.351…2.378 |

| `sd     "\"" "'"   *.json > /dev/null` | **0.997 ± 0.006** | 0.987…1.007 |



Result: ~2.35 times faster



**Regex replacement on a ~55M json file**:



```sh

hyperfine --warmup 3 --export-markdown out.md \

  'sed -E "s:(\w+):\1\1:g"    dump.json > /dev/null' \

  'sed    "s:\(\w\+\):\1\1:g" dump.json > /dev/null' \

  'sd     "(\w+)" "$1$1"      dump.json > /dev/null'

```



| Command | Mean [s] | Min…Max [s] |

|:---|---:|---:|

| `sed -E "s:(\w+):\1\1:g"    dump.json > /dev/null` | 11.315 ± 0.215 | 11.102…11.725 |

| `sed    "s:\(\w\+\):\1\1:g" dump.json > /dev/null` | 11.239 ± 0.208 | 11.057…11.762 |

| `sd     "(\w+)" "$1$1"      dump.json > /dev/null` | **0.942 ± 0.004** | 0.936…0.951 |



Result: ~11.93 times faster



## Installation



Install through

[`cargo`](https://doc.rust-lang.org/cargo/getting-started/installation.html) with

`cargo install sd`, or through various package managers



[![Packaging status](https://repology.org/badge/vertical-allrepos/sd-find-replace.svg?exclude_unsupported=1)](https://repology.org/project/sd-find-replace/versions)



## Quick Guide



1. **String-literal mode**. By default, expressions are treated as regex. Use `-F` or `--fixed-strings` to disable regex.



   ```sh

   > echo 'lots((([]))) of special chars' | sd -F '((([])))' ''

   lots of special chars

   ```



2. **Basic regex use** - let's trim some trailing whitespace



   ```sh

   > echo 'lorem ipsum 23   ' | sd '\s+$' ''

   lorem ipsum 23

   ```



3. **Capture groups**



   Indexed capture groups:



   ```sh

   > echo 'cargo +nightly watch' | sd '(\w+)\s+\+(\w+)\s+(\w+)' 'cmd: $1, channel: $2, subcmd: $3'

   cmd: cargo, channel: nightly, subcmd: watch

   ```



   Named capture groups:



   ```sh

   > echo "123.45" | sd '(?P\d+)\.(?P\d+)' '$dollars dollars and $cents cents'

   123 dollars and 45 cents

   ```



   In the unlikely case you stumble upon ambiguities, resolve them by using `${var}` instead of `$var`. Here's an example:



   ```sh

   > echo '123.45' | sd '(?P\d+)\.(?P\d+)' '$dollars_dollars and $cents_cents'

    and



   > echo '123.45' | sd '(?P\d+)\.(?P\d+)' '${dollars}_dollars and ${cents}_cents'

   123_dollars and 45_cents

   ```



4. **Find & replace in a file**



   ```sh

   > sd 'window.fetch' 'fetch' http.js

   ```



   That's it. The file is modified in-place.



   To preview changes:



   ```sh

   > sd -p 'window.fetch' 'fetch' http.js

   ```



5. **Find & replace across project**



   This example uses [fd](https://github.com/sharkdp/fd).



   Good ol' unix philosophy to the rescue.



   ```sh

   fd --type file --exec sd 'from "react"' 'from "preact"'

   ```



   Same, but with backups (consider version control).



   ```bash

   fd --type file --exec cp {} {}.bk \; --exec sd 'from "react"' 'from "preact"'

   ```



### Edge cases

sd will interpret every argument starting with `-` as a (potentially unknown) flag.

The common convention of using `--` to signal the end of flags is respected:



```bash

$ echo "./hello foo" | sd "foo" "-w"

error: Found argument '-w' which wasn't expected, or isn't valid in this context



USAGE:

    sd [OPTIONS]   [files]...



For more information try --help

$ echo "./hello foo" | sd "foo" -- "-w"

./hello -w

$ echo "./hello --foo" | sd -- "--foo" "-w"

./hello -w

```



### Escaping special characters

To escape the `$` character, use `$$`:



```bash

❯ echo "foo" | sd 'foo' '$$bar'

$bar

```