java-cli-script

Name: java-cli-script
Author: AdamBien

40stars10forks

How to install java-cli-script?

adambien/airails/java-cli-script

$npx -y skills add AdamBien/airails --skill java-cli-script

Installs into the current project.

Summary

Create zero-dependency, single-file executable Java scripts for system-wide use via PATH. Use when asked to create a single-file Java shell script, system utility, PATH-installed Java tool, or shebang-launched Java program without the .java extension. Triggers on "Java script", "

Files · 1

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SKILL.md

1	Create or maintain a zero-dependency, single-file executable Java script using $ARGUMENTS. Apply all rules below strictly.
2
3	## Purpose
4
5	These are self-contained, single-file Java scripts installed in a PATH directory (e.g., `/usr/local/bin`) and invoked like any shell command — no project structure, no build tool, no `.java` extension.
6
7	## Composition
8
9	- Follow `/java-conventions` for all generic Java 25 style, syntax, naming, methods, streams, exceptions, and comments
10	- The rules below specialize `/java-conventions` for single-file source-mode scripts; when this skill is silent on a topic, `/java-conventions` applies
11
12	## Single-File Constraint
13
14	- Everything lives in one file — all logic, records, enums, sealed types, and helper methods
15	- If the script grows beyond what fits comfortably in a single file, suggest switching to the `java-cli-app` skill instead
16	- No multi-file source-code programs — this skill is strictly for single-file scripts
17
18	## Build
19
20	- Use Java 25 source-file mode — no build tool, no compilation step
21	- Never use the `.java` extension — scripts are executable files with a lowercase filename and a shebang
22	- Never use `--enable-preview` in the shebang — Java 25 is a GA release, all features used here are standard
23	- The shebang line is always:
24
25	```
26	#!/usr/bin/env -S java --source 25
27	```
28
29	- Save with a short, descriptive, lowercase command name (e.g., `jsonformat`, `portcheck`, `sysinfo`)
30	- Never use dashes in filenames (e.g., `hello-world`) — Java source-file mode does not support them. Use camelCase instead (e.g., `helloWorld`)
31	- Mark executable: `chmod +x scriptname`
32	- Install by copying or symlinking to a PATH directory: `cp scriptname /usr/local/bin/` or `ln -s $(pwd)/scriptname /usr/local/bin/scriptname`
33
34	## Script Structure
35
36	A minimal script:
37
38	```
39	#!/usr/bin/env -S java --source 25
40
41	void main(String... args) throws Exception {
42	// ...
43	}
44	```
45
46	## Naming Convention
47
48	- The script's filename is its application name — use it consistently in all output: version strings, help text, usage lines, and error messages
49	- Derive the application name dynamically at startup using `MethodHandles.lookup().lookupClass().getName()` — in source-file mode, the class name matches the filename, so there is nothing to hardcode or keep in sync
50
51	## Version Management
52
53	- Suggest maintaining a `String version = "YYYY-MM-DD.N";` instance variable (e.g., `String version = "2026-02-20.1";`)
54	- On every change, update the date to the current date and increase the last number
55	- Print the script name and version on startup as the first line of output (e.g., `IO.println(name + " " + version);`)
56	- Support `-version` flag to print the version — only for scripts that accept additional arguments
57
58	## Main Method Conventions
59
60	- Use `void main(String... args) throws Exception` — PATH-installed scripts always accept arguments; declaring `throws Exception` keeps the code clean by avoiding try-catch boilerplate for checked exceptions like `IOException`
61	- Parse arguments manually for simple scripts with few flags
62	- For scripts with multiple options or complex argument handling, use the `/zargs` skill to generate an enum-based argument parser — it remains zero-dependency and single-file
63
64	## Argument Handling
65
66	- Scripts with no additional arguments: do not introduce `-help` or `-version` flags — the script should just do its work
67	- Scripts with additional arguments: support both `-help` and `-version` flags
68	- Use clear, descriptive error messages for invalid input
69	- Exit with code 0 on success, non-zero on failure
70
71	Script with additional arguments — include `-help` and `-version`:
72
73	```
74	String name = MethodHandles.lookup().lookupClass().getName();
75	String version = "2026-02-20.1";
76
77	void main(String... args) throws Exception {
78	IO.println(name + " " + version);
79	if (args.length == 0 \|\| args[0].equals("-help")) {
80	IO.println("""
81	Usage: %s <input> [options]
82	-help Show this help
83	-version Show version
84	""".formatted(name));
85	return;
86	}
87	if (args[0].equals("-version")) {
88	return;
89	}
90	// ...
91	}
92	```
93
94	## Convenience Scripts for an Existing java-cli-app or JAR
95
96	When asked for an executable convenience script for a `/java-cli-app` project or an existing JAR, do not replicate the application's logic in the script. The script stays a single-file source script whose `main` calls into the JAR's classes. Instead:
97
98	-

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6 picks

Type

java-cli-script

40stars10forks

View on GitHub

How to install java-cli-script?

adambien/airails/java-cli-script

$npx -y skills add AdamBien/airails --skill java-cli-script

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	Create or maintain a zero-dependency, single-file executable Java script using $ARGUMENTS. Apply all rules below strictly.
2
3	## Purpose
4
5	These are self-contained, single-file Java scripts installed in a PATH directory (e.g., `/usr/local/bin`) and invoked like any shell command — no project structure, no build tool, no `.java` extension.
6
7	## Composition
8
9	- Follow `/java-conventions` for all generic Java 25 style, syntax, naming, methods, streams, exceptions, and comments
10	- The rules below specialize `/java-conventions` for single-file source-mode scripts; when this skill is silent on a topic, `/java-conventions` applies
11
12	## Single-File Constraint
13
14	- Everything lives in one file — all logic, records, enums, sealed types, and helper methods
15	- If the script grows beyond what fits comfortably in a single file, suggest switching to the `java-cli-app` skill instead
16	- No multi-file source-code programs — this skill is strictly for single-file scripts
17
18	## Build
19
20	- Use Java 25 source-file mode — no build tool, no compilation step
21	- Never use the `.java` extension — scripts are executable files with a lowercase filename and a shebang
22	- Never use `--enable-preview` in the shebang — Java 25 is a GA release, all features used here are standard
23	- The shebang line is always:
24
25	```
26	#!/usr/bin/env -S java --source 25
27	```
28
29	- Save with a short, descriptive, lowercase command name (e.g., `jsonformat`, `portcheck`, `sysinfo`)
30	- Never use dashes in filenames (e.g., `hello-world`) — Java source-file mode does not support them. Use camelCase instead (e.g., `helloWorld`)
31	- Mark executable: `chmod +x scriptname`
32	- Install by copying or symlinking to a PATH directory: `cp scriptname /usr/local/bin/` or `ln -s $(pwd)/scriptname /usr/local/bin/scriptname`
33
34	## Script Structure
35
36	A minimal script:
37
38	```
39	#!/usr/bin/env -S java --source 25
40
41	void main(String... args) throws Exception {
42	// ...
43	}
44	```
45
46	## Naming Convention
47
48	- The script's filename is its application name — use it consistently in all output: version strings, help text, usage lines, and error messages
49	- Derive the application name dynamically at startup using `MethodHandles.lookup().lookupClass().getName()` — in source-file mode, the class name matches the filename, so there is nothing to hardcode or keep in sync
50
51	## Version Management
52
53	- Suggest maintaining a `String version = "YYYY-MM-DD.N";` instance variable (e.g., `String version = "2026-02-20.1";`)
54	- On every change, update the date to the current date and increase the last number
55	- Print the script name and version on startup as the first line of output (e.g., `IO.println(name + " " + version);`)
56	- Support `-version` flag to print the version — only for scripts that accept additional arguments
57
58	## Main Method Conventions
59
60	- Use `void main(String... args) throws Exception` — PATH-installed scripts always accept arguments; declaring `throws Exception` keeps the code clean by avoiding try-catch boilerplate for checked exceptions like `IOException`
61	- Parse arguments manually for simple scripts with few flags
62	- For scripts with multiple options or complex argument handling, use the `/zargs` skill to generate an enum-based argument parser — it remains zero-dependency and single-file
63
64	## Argument Handling
65
66	- Scripts with no additional arguments: do not introduce `-help` or `-version` flags — the script should just do its work
67	- Scripts with additional arguments: support both `-help` and `-version` flags
68	- Use clear, descriptive error messages for invalid input
69	- Exit with code 0 on success, non-zero on failure
70
71	Script with additional arguments — include `-help` and `-version`:
72
73	```
74	String name = MethodHandles.lookup().lookupClass().getName();
75	String version = "2026-02-20.1";
76
77	void main(String... args) throws Exception {
78	IO.println(name + " " + version);
79	if (args.length == 0 \|\| args[0].equals("-help")) {
80	IO.println("""
81	Usage: %s <input> [options]
82	-help Show this help
83	-version Show version
84	""".formatted(name));
85	return;
86	}
87	if (args[0].equals("-version")) {
88	return;
89	}
90	// ...
91	}
92	```
93
94	## Convenience Scripts for an Existing java-cli-app or JAR
95
96	When asked for an executable convenience script for a `/java-cli-app` project or an existing JAR, do not replicate the application's logic in the script. The script stays a single-file source script whose `main` calls into the JAR's classes. Instead:
97
98	-

People who liked this also viewed

6 picks

Type