Include filename in screenshot-path

resources/default-config.kdl

@@ -112,7 +112,8 @@ gaps 16
 
 // You can change the path where screenshots are saved.
 // A ~ at the front will be expanded to the home directory.
-screenshot-path "~/Pictures/Screenshots"
+// The path is formatted with strftime(3) to give you the screenshot date and time.
+screenshot-path "~/Pictures/Screenshots/Screenshot from %Y-%m-%d %H-%M-%S.png"
 
 // You can also set this to null to disable saving screenshots to disk.
 // screenshot-path null

src/config.rs

@@ -26,8 +26,14 @@ pub struct Config {
     pub preset_column_widths: Vec<PresetWidth>,
     #[knuffel(child, unwrap(argument), default = 16)]
     pub gaps: u16,
-    #[knuffel(child, unwrap(argument), default = Some(PathBuf::from("~/Pictures/Screenshots")))]
-    pub screenshot_path: Option<PathBuf>,
+    #[knuffel(
+        child,
+        unwrap(argument),
+        default = Some(String::from(
+            "~/Pictures/Screenshots/Screenshot from %Y-%m-%d %H-%M-%S.png"
+        )))
+    ]
+    pub screenshot_path: Option<String>,
     #[knuffel(child, default)]
     pub binds: Binds,
     #[knuffel(child, default)]
@@ -541,7 +547,7 @@ mod tests {
 
             gaps 8
 
-            screenshot-path "~/Screenshots"
+            screenshot-path "~/Screenshots/screenshot.png"
 
             binds {
                 Mod+T { spawn "alacritty"; }
@@ -617,7 +623,7 @@ mod tests {
                     PresetWidth::Fixed(1280),
                 ],
                 gaps: 8,
-                screenshot_path: Some(PathBuf::from("~/Screenshots")),
+                screenshot_path: Some(String::from("~/Screenshots/screenshot.png")),
                 binds: Binds(vec![
                     Bind {
                         key: Key {

src/niri.rs

@@ -2077,8 +2077,6 @@ impl Niri {
 
         use smithay::backend::renderer::element::utils::{Relocate, RelocateRenderElement};
 
-        use crate::utils::add_screenshot_filename;
-
         let _span = tracy_client::span!("Niri::screenshot_all_outputs");
 
         let mut elements = vec![];
@@ -2103,15 +2101,13 @@ impl Niri {
         let pixels = render_to_vec(renderer, size, Scale::from(1.), Fourcc::Abgr8888, &elements)?;
 
         let path = make_screenshot_path(&self.config.borrow())
-            .and_then(|path| match path {
-                Some(path) => Ok(path),
-                None => {
-                    let mut path = env::temp_dir();
-                    add_screenshot_filename(&mut path)?;
-                    Ok(path)
-                }
-            })
-            .context("error making screenshot path")?;
+            .ok()
+            .flatten()
+            .unwrap_or_else(|| {
+                let mut path = env::temp_dir();
+                path.push("screenshot.png");
+                path
+            });
         debug!("saving screenshot to {path:?}");
 
         thread::spawn(move || {

src/utils.rs

@@ -1,4 +1,4 @@
-use std::ffi::OsStr;
+use std::ffi::{CString, OsStr};
 use std::io::{self, Write};
 use std::os::unix::prelude::OsStrExt;
 use std::os::unix::process::CommandExt;
@@ -24,23 +24,14 @@ pub fn center(rect: Rectangle<i32, Logical>) -> Point<i32, Logical> {
 }
 
 pub fn make_screenshot_path(config: &Config) -> anyhow::Result<Option<PathBuf>> {
-    let Some(mut path) = config.screenshot_path.clone() else {
+    let Some(path) = &config.screenshot_path else {
         return Ok(None);
     };
 
-    if let Ok(rest) = path.strip_prefix("~") {
-        let dirs = UserDirs::new().context("error retrieving home directory")?;
-        path = [dirs.home_dir(), rest].iter().collect();
-    }
+    let format = CString::new(path.clone()).context("path must not contain nul bytes")?;
 
-    add_screenshot_filename(&mut path)?;
-
-    Ok(Some(path))
-}
-
-pub fn add_screenshot_filename(path: &mut PathBuf) -> anyhow::Result<()> {
-    let mut buf = [0u8; 256];
-    let name;
+    let mut buf = [0u8; 2048];
+    let mut path;
     unsafe {
         let time = libc::time(null_mut());
         ensure!(time != -1, "error in time()");
@@ -48,21 +39,18 @@ pub fn add_screenshot_filename(path: &mut PathBuf) -> anyhow::Result<()> {
         let tm = libc::localtime(&time);
         ensure!(!tm.is_null(), "error in localtime()");
 
-        let format = b"Screenshot from %Y-%m-%d %H-%M-%S.png\0";
-        let rv = libc::strftime(
-            buf.as_mut_ptr().cast(),
-            buf.len(),
-            format.as_ptr().cast(),
-            tm,
-        );
+        let rv = libc::strftime(buf.as_mut_ptr().cast(), buf.len(), format.as_ptr(), tm);
         ensure!(rv != 0, "error formatting time");
 
-        name = OsStr::from_bytes(&buf[..rv]);
+        path = PathBuf::from(OsStr::from_bytes(&buf[..rv]));
     }
 
-    path.push(name);
+    if let Ok(rest) = path.strip_prefix("~") {
+        let dirs = UserDirs::new().context("error retrieving home directory")?;
+        path = [dirs.home_dir(), rest].iter().collect();
+    }
 
-    Ok(())
+    Ok(Some(path))
 }
 
 /// Spawns the command to run independently of the compositor.