Synsh: Shell Pipeline Synthesizer

Synsh (synsh.dev) automatically creates shell pipelines from example inputs and outputs.

Example

Suppose we want to find a pipeline to transform the following comma-separated input:

Arthur,2
Octavia,3
Margaret,1

to the following space-separated output, in which each line has been sorted by the numeric value, and the number comes first:

1 Margaret
2 Arthur
3 Octavia

First, we enter the input into the "input" text box:

Input

Arthur,2
Octavia,3
Margaret,1

Output

Pipeline

Waiting for input.

Next, we enter the desired output into the "output" text box. Suppose that, to start with, we have only entered the first line of the output so far. Synsh searches for a pipeline mapping the input to the output as we type, so it will find a pipeline that maps our complete input to our partially-entered output:

Input

Arthur,2
Octavia,3
Margaret,1

Output

1 Margaret

Pipeline

# 1. Replace "\n" by "\t".
# 2. Select field 3, separated by "\t".
# 3. Select fields 1 and 2 in order 2 and 1, separated by ",", with output
#    fields separated by " ".
tr '\n' '\t' | cut -f 3 | awk -F , '{ print $2, $1 }'

Note that, along with the pipeline itself, Synsh outputs a comment describing what the pipeline does.

Note also that Synsh displays two buttons above the pipeline:

The link button: pressing this button gives you a URL to use to share the current page, including the input, output, and the pipeline that Synsh found.
The copy button: Pressing this button copies the pipeline to the clipboard.

Once we've finished entering the full output, Synsh finds and displays the pipeline we want:

Input

Arthur,2
Octavia,3
Margaret,1

Output

1 Margaret
2 Arthur
3 Octavia

Pipeline

# 1. Select fields 1 and 2 in order 2 and 1, separated by ",".
# 2. Sort lines by alphanumeric value.
# 3. Replace "," by " ".
awk -F , 'BEGIN { OFS = "," } { print $2, $1 }' | sort | tr , ' '

Keeping Up To Date

To keep track of updates to Synsh, see the Synsh blog.

Feedback

Please send all feedback to Pat Rondon: pat.rondon@gmail.com.