Add functions for fetching workflow env variables

src/env.rs

@@ -0,0 +1,88 @@
+//! Environment variables in workflows.
+//!
+//! See <https://www.alfredapp.com/help/workflows/script-environment-variables/>
+
+use std::env;
+use std::ffi::OsStr;
+use std::path::PathBuf;
+
+/// Fetches the environment variable `key` from the current process.
+///
+/// This function is similar to [`env::var(key).ok()`][env::var] but it also
+/// maps an empty string to `None`.
+///
+/// # None
+///
+/// Returns `None` in the following cases:
+/// - if the environment variable is not present.
+/// - if the environment variable is not valid Unicode.
+/// - if the environment variable is set to an empty string.
+///
+/// # Panics
+///
+/// This function may panic if key is empty, contains an ASCII equals sign `'='`
+/// or the NUL character `'\0'`, or when the value contains the NUL character.
+pub fn var<K: AsRef<OsStr>>(key: K) -> Option<String> {
+    env::var(key).ok().filter(|s| !s.is_empty())
+}
+
+/// Whether or not the user currently has the debug panel open.
+pub fn is_debug() -> bool {
+    var("alfred_debug").as_deref() == Some("1")
+}
+
+/// The location of the `Alfred.alfredpreferences` directory.
+///
+/// If a user has synced their settings, this will allow you to find out where
+/// their settings are.
+pub fn preferences() -> Option<PathBuf> {
+    var("alfred_preferences").map(PathBuf::from)
+}
+
+/// The Alfred version that is currently running.
+///
+/// This may be useful if your workflow depends on particular Alfred features.
+pub fn version() -> Option<String> {
+    var("alfred_version")
+}
+
+/// The Alfred build version that is currently running.
+///
+/// This may be useful if your workflow depends on particular Alfred features.
+pub fn version_build() -> Option<u32> {
+    var("alfred_version_build").and_then(|s| s.parse().ok())
+}
+
+/// The bundle ID of the currently running workflow.
+pub fn workflow_bundle_id() -> Option<String> {
+    var("alfred_workflow_bundleid")
+}
+
+/// The name of the currently running workflow.
+pub fn workflow_name() -> Option<String> {
+    var("alfred_workflow_name")
+}
+
+/// The unique ID of the currently running workflow.
+pub fn workflow_uid() -> Option<String> {
+    var("alfred_workflow_uid")
+}
+
+/// The version of the currently running workflow.
+pub fn workflow_version() -> Option<String> {
+    var("alfred_workflow_version")
+}
+
+/// The recommended directory for volatile workflow data.
+///
+/// This will only be populated if your workflow has a bundle id set.
+pub fn workflow_cache() -> Option<PathBuf> {
+    var("alfred_workflow_cache").map(PathBuf::from)
+}
+
+/// The recommended directory for non-volatile workflow data.
+///
+/// This will only be populated if your workflow has a bundle id set.
+pub fn workflow_data() -> Option<PathBuf> {
+    var("alfred_workflow_data").map(PathBuf::from)
+}

src/lib.rs

@@ -30,6 +30,8 @@
 //! # }
 //! ```
 
+pub mod env;
+
 use std::collections::HashMap;
 use std::io;
 use std::path::PathBuf;