pr: print 56 lines of content with 5 blank trailer and header lines

Cargo.toml

@@ -64,6 +64,7 @@ feat_common_core = [
     "nl",
     "od",
     "paste",
+    "pr",
     "printenv",
     "printf",
     "ptx",
@@ -285,6 +286,7 @@ od       = { optional=true, version="0.0.4", package="uu_od", path="src/uu/od" }
 paste    = { optional=true, version="0.0.4", package="uu_paste", path="src/uu/paste" }
 pathchk  = { optional=true, version="0.0.4", package="uu_pathchk", path="src/uu/pathchk" }
 pinky    = { optional=true, version="0.0.4", package="uu_pinky", path="src/uu/pinky" }
+pr       = { optional=true, path="src/pr" }
 printenv = { optional=true, version="0.0.4", package="uu_printenv", path="src/uu/printenv" }
 printf   = { optional=true, version="0.0.4", package="uu_printf", path="src/uu/printf" }
 ptx      = { optional=true, version="0.0.4", package="uu_ptx", path="src/uu/ptx" }

src/pr/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "pr"
+version = "0.0.1"
+authors = ["Tilak Patidar <tilakpatidar@gmail.com>"]
+build = "../../mkmain.rs"
+
+[lib]
+name = "uu_pr"
+path = "pr.rs"
+
+[dependencies]
+getopts = "0.2.18"
+time = "0.1.40"
+
+[dependencies.uucore]
+path = "../uucore"
+features = ["libc"]
+
+[[bin]]
+name = "pr"
+path = "../../uumain.rs"

src/pr/pr.rs

@@ -0,0 +1,139 @@
+#![crate_name = "uu_pr"]
+
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE file
+// that was distributed with this source code.
+//
+
+extern crate getopts;
+
+//#[macro_use]
+//extern crate uucore;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::vec::Vec;
+//use uucore::fs::is_stdin_interactive;
+
+
+static NAME: &str = "pr";
+static VERSION: &str = env!("CARGO_PKG_VERSION");
+static LINES_PER_PAGE: usize = 66;
+static HEADER_LINES_PER_PAGE: usize = 5;
+static TRAILER_LINES_PER_PAGE: usize = 5;
+static CONTENT_LINES_PER_PAGE: usize = LINES_PER_PAGE - HEADER_LINES_PER_PAGE - TRAILER_LINES_PER_PAGE;
+
+pub fn uumain(args: Vec<String>) -> i32 {
+    let mut opts = getopts::Options::new();
+
+    opts.optopt(
+        "h",
+        "",
+        "Use the string header to replace the file name \
+     in the header line.",
+        "STRING",
+    );
+    opts.optflag("h", "help", "display this help and exit");
+    opts.optflag("V", "version", "output version information and exit");
+
+    let matches = match opts.parse(&args[1..]) {
+        Ok(m) => m,
+        Err(e) => panic!("Invalid options\n{}", e),
+    };
+
+    if matches.opt_present("version") {
+        println!("{} {}", NAME, VERSION);
+        return 0;
+    }
+
+
+    if matches.opt_present("help") || matches.free.is_empty() {
+        println!("{} {} -- print files", NAME, VERSION);
+        println!();
+        println!("Usage: {} [+page] [-column] [-adFfmprt] [[-e] [char] [gap]]
+        [-L locale] [-h header] [[-i] [char] [gap]]
+        [-l lines] [-o offset] [[-s] [char]] [[-n] [char]
+        [width]] [-w width] [-] [file ...].", NAME);
+        println!();
+        println!(
+            "{}",
+            opts.usage(
+                "The pr utility is a printing and pagination filter
+     for text files.  When multiple input files are spec-
+     ified, each is read, formatted, and written to stan-
+     dard output.  By default, the input is separated
+     into 66-line pages, each with
+
+     o   A 5-line header with the page number, date,
+         time, and the pathname of the file.
+
+     o   A 5-line trailer consisting of blank lines.
+
+     If standard output is associated with a terminal,
+     diagnostic messages are suppressed until the pr
+     utility has completed processing.
+
+     When multiple column output is specified, text col-
+     umns are of equal width.  By default text columns
+     are separated by at least one <blank>.  Input lines
+     that do not fit into a text column are truncated.
+     Lines are not truncated under single column output."
+            )
+        );
+        if matches.free.is_empty() {
+            return 1;
+        }
+        return 0;
+    }
+
+    let path = &matches.free[0];
+    open(&path);
+
+    0
+}
+
+fn open(path: &str) -> std::io::Result<()> {
+    let file = File::open(path)?;
+    let lines = BufReader::new(file).lines();
+    let mut i = 0;
+    let mut page: i32 = 0;
+    let mut buffered_content: Vec<String> = Vec::new();
+    for line in lines {
+        if i == CONTENT_LINES_PER_PAGE {
+            page = page + 1;
+            i = 0;
+            print!("{}", print_page(&buffered_content));
+            buffered_content.clear();
+        }
+        i = i + 1;
+        buffered_content.push(line?);
+    }
+    if i != 0 {
+        print!("{}", print_page(&buffered_content));
+        buffered_content.clear();
+    }
+    Ok(())
+}
+
+fn print_page(lines: &Vec<String>) -> String {
+    let mut page_content: Vec<String> = Vec::new();
+    let header_content = header_content();
+    let trailer_content = trailer_content();
+    assert_eq!(lines.len() <= CONTENT_LINES_PER_PAGE, true, "Only {} lines of content allowed in a pr output page", CONTENT_LINES_PER_PAGE.to_string());
+    assert_eq!(header_content.len(), HEADER_LINES_PER_PAGE, "Only {} lines of content allowed in a pr header", HEADER_LINES_PER_PAGE.to_string());
+    assert_eq!(trailer_content.len(), TRAILER_LINES_PER_PAGE, "Only {} lines of content allowed in a pr trailer", TRAILER_LINES_PER_PAGE.to_string());
+    page_content.extend(header_content);
+    for x in lines {
+        page_content.push(x.to_string());
+    }
+    page_content.extend(trailer_content);
+    page_content.join("\n")
+}
+
+fn header_content() -> Vec<String> {
+    vec!["".to_string(), "".to_string(), "".to_string(), "".to_string(), "".to_string()]
+}
+
+fn trailer_content() -> Vec<String> {
+    vec!["".to_string(), "".to_string(), "".to_string(), "".to_string(), "".to_string()]
+}