hautils

commit c1f3bd94162c07f4890655a426c2262adb4ecd57
parent f7db4cf8582d596d7c81c04f2b63642111cddf02
Author: Byron Torres <b@torresjrjr.com>
Date:   Fri, 20 Aug 2021 11:16:51 +0100

nl: new command

Only implements -iswv flags for now.
Does not implement logical page delimiters.

Diffstat:
M
.gitignore
 | 
5
+++--
M
Makefile
 | 
2
++
A
nl.ha
 | 
110
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 115 insertions(+), 2 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -1,6 +1,7 @@
 cat
 false
-true
+head
+nl
 tee
+true
 uname
-head
diff --git a/Makefile b/Makefile
@@ -7,6 +7,7 @@ utils=\
 	cat \
 	false \
 	head \
+	nl \
 	tee \
 	true \
 	uname
@@ -25,6 +26,7 @@ clean:
 cat: cat.ha main/main.ha
 false: false.ha
 head: head.ha
+nl: nl.ha
 tee: tee.ha
 true: true.ha
 uname: uname.ha
diff --git a/nl.ha b/nl.ha
@@ -0,0 +1,110 @@
+use bufio;
+use fmt;
+use fs;
+use getopt;
+use io;
+use main;
+use os;
+use strconv;
+
+export fn utilmain() (void | main::error) = {
+	const helplist: [_]getopt::help = [
+		"line numbering filter",
+		('p', "do not restart numbering at logical page delimiters"),
+		('b', "type", "set body line numbering strategy"),
+		('d', "delim", "set delimiter for new pages"),
+		('f', "type", "set footer line numbering strategy"),
+		('h', "type", "set header line numbering strategy"),
+		('i', "incr", "amount to increment each page"),
+		('l', "num", "number of consecutive blank lines considered one"),
+		('n', "format", "set line number format"),
+		('s', "sep", "set separator to place between line number and text"),
+		('v', "startnum", "initial value for each page"),
+		('w', "width", "number of columns for numbers"),
+		"[file]"
+	];
+	const cmd = getopt::parse(os::args, helplist...);
+	defer getopt::finish(&cmd);
+
+	let incr = 1;
+	let sep = "\t";
+	let width: uint = 6;
+	let startnum = 1;
+
+	for (let i = 0z; i < len(cmd.opts); i += 1) {
+		const opt = cmd.opts[i];
+		switch (opt.0) {
+			'b' => abort("TODO: implement -b flag"),
+			'd' => abort("TODO: implement -d flag"),
+			'f' => abort("TODO: implement -f flag"),
+			'h' => abort("TODO: implement -h flag"),
+			'i' => incr = match (strconv::stoi(opt.1)) {
+				(strconv::invalid | strconv::overflow) =>
+					fmt::fatal("Error: -i: argument must be an integer"),
+				incr: int => incr,
+			},
+			'l' => abort("TODO: implement -l flag"),
+			'n' => abort("TODO: implement -n flag"),
+			'p' => abort("TODO: implement -p flag"),
+			's' => sep = opt.1,
+			'w' => width = match (strconv::stou(opt.1)) {
+				(strconv::invalid | strconv::overflow) =>
+					fmt::fatal("Error: -w: argument must be an ingeter"),
+				width: uint =>
+					if (width <= 0)
+						fmt::fatal("Error: -w: width must be greater than 0")
+					else
+						width,
+			},
+			'v' => startnum = match (strconv::stoi(opt.1)) {
+				(strconv::invalid | strconv::overflow) => {
+					fmt::errorln("Error: -v: argument must be an integer")?;
+					getopt::printusage(os::stderr, os::args[0], helplist);
+					os::exit(1);
+				},
+				startnum: int => startnum,
+			},
+		};
+	};
+
+	if (len(cmd.args) > 1) {
+		getopt::printusage(os::stderr, os::args[0], helplist);
+		os::exit(1);
+	};
+
+	const use_file = len(cmd.args) == 1 && cmd.args[0] != "-";
+	const input = switch (use_file) {
+		true => match (os::open(cmd.args[0])) {
+			err: fs::error => fmt::fatal("Error opening '{}': {}",
+				cmd.args[0], fs::strerror(err)),
+			file: *io::stream => {
+				static const rbuf: [os::BUFSIZ]u8 = [0...];
+				static const wbuf: [os::BUFSIZ]u8 = [0...];
+				bufio::buffered(file, rbuf, wbuf);
+			},
+		},
+		false => os::stdin,
+	};
+	defer io::close(input);
+
+	// prepares line number format string, e.g.: "{0:6}{1}"
+	const fmtstr = fmt::asprintf("{{0:{0}}}{{1}}", width);
+
+	let linenum = startnum;
+
+	for (true) {
+		const line = match (bufio::scanline(input)) {
+			err: io::error => return err,
+			io::EOF        => break,
+			line: []u8     => line,
+		};
+		defer free(line);
+
+		if (len(line) != 0) {
+			fmt::printf(fmtstr, linenum, sep)?;
+			linenum += incr;
+		};
+		io::write(os::stdout, line)?;
+		fmt::println()?;
+	};
+};