Use `more` as a fallback pager

src/helper.rs

@@ -42,7 +42,7 @@ pub fn pipe() -> (i32, i32) {
     (fds[0], fds[1])
 }
 
-pub fn found_in_path(exec: &str) -> bool {
+fn found_in_path(exec: &str) -> bool {
     if let Some(path) = env::var_os("PATH") {
         let paths = env::split_paths(&path);
         for path in paths {
@@ -54,9 +54,17 @@ pub fn found_in_path(exec: &str) -> bool {
     false
 }
 
+pub fn default_pager() -> Option<CString> {
+    if found_in_path("more") {
+        CString::new("more").ok()
+    } else {
+        None
+    }
+}
+
 #[cfg(test)]
 mod tests {
-    use super::*;
+    use super::found_in_path;
 
     #[test]
     fn ls_found_in_path() {

src/lib.rs

@@ -35,11 +35,12 @@
 
 extern crate libc;
 
+use std::ffi::CString;
 use std::ptr;
 
 mod helper;
 
-use helper::{getenv, fork, close, dup2, execvp, pipe};
+use helper::{getenv, fork, close, dup2, execvp, pipe, default_pager};
 
 const DEFAULT_PAGER_ENV: &'static str = "PAGER";
 
@@ -69,7 +70,7 @@ impl Pager {
     }
 
     pub fn setup(&mut self) {
-        if let Some(pager) = getenv(&self.env) {
+        if let Some(pager) = self.get_pager() {
             let (pager_stdin, main_stdout) = pipe();
             let pid = fork();
             match pid {
@@ -94,4 +95,8 @@ impl Pager {
             }
         }
     }
+
+    fn get_pager(&self) -> Option<CString> {
+        getenv(&self.env).or_else(default_pager)
+    }
 }