add local_util.rs

src/local_util.rs

@@ -0,0 +1,62 @@
+
+use std:: {
+    fs::File,
+    path::Path,
+    io::prelude::*,
+};
+
+use rust_util::*;
+
+pub fn get_term_width() -> Option<usize> {
+    match term_size::dimensions() {
+        None => None,
+        Some((w, _h)) => Some(w),
+    }
+}
+
+// thanks https://blog.csdn.net/star_xiong/article/details/89401149
+pub fn find_char_boundary(s: &str, index: usize) -> usize {
+    if s.len() <= index {
+        return index;
+    }
+    let mut new_index = index;
+    while !s.is_char_boundary(new_index) {
+        new_index += 1;
+    }
+    new_index
+}
+
+pub fn get_term_width_message(message: &str, left: usize) -> String {
+    match get_term_width() {
+        None => message.to_string(),
+        Some(w) => {
+            let len = message.len();
+            if w > len {
+               return message.to_string();
+            }
+            let mut s = String::new();
+            s.push_str(&message[0..find_char_boundary(&message, w-10-5-left)]);
+            s.push_str("[...]");
+            s.push_str(&message[find_char_boundary(&message, len-10)..]);
+            s
+        },
+    }
+}
+
+pub fn read_file_content(file: &Path, large_file_len: u64) -> XResult<String> {
+    if ! file.exists() {
+        return Err(new_box_error(&format!("File not exists: {:?}", file)));
+    }
+    if ! file.is_file() {
+        return Err(new_box_error(&format!("File is not file: {:?}", file)));
+    }
+    let file_len = file.metadata()?.len();
+    if file_len > large_file_len {
+        return Err(new_box_error(&format!("File too large: {:?}, len: {}", file, file_len)));
+    }
+    let mut f = File::open(file)?;
+    let mut content = String::new();
+    f.read_to_string(&mut content)?;
+
+    Ok(content)
+}