HILEX(1) General Commands Manual HILEX(1)

hilex — syntax highlighter

hilex [-t] [-f format] [-l lexer] [-n name] [-o opts] [file]

The hilex utility syntax highlights the contents of file or standard input and formats it on standard output.

The arguments are as follows:

format
Set the output format. See Output Formats. The default format is ansi.
lexer
Set the input lexer. See Input Lexers. The default input lexer is inferred from name or the first line of input.
name
Set the name used to infer the input lexer. The default is the final component of file.
opts
Set output format options. opts is a comma-separated list of options. Options for each output format are documented in Output Formats.
Default to the text input lexer if one cannot be inferred.

Output ANSI terminal control sequences. If standard output is a terminal and standard input is not being read, output is piped to PAGER with LESS=FRX if it is not already set.
Output HTML elements with the following classes:

operators
numbers
keywords
identifiers
macros
comments
strings
character escapes
format strings
variable substitutions

The options are as follows:

Output an HTML document containing a pre element.
Output inline style attributes rather than classes.
Wrap the output in a pre element with the class .
=url
With document, use the external stylesheet url. If unset, default styles are included in a style element.
=n
With document, inline or pre, set the property to n.
=...
With document, set the title element text. The default title is the same as name.
Output IRC formatting codes. The options are as follows:
Use the IRCCloud monospace formatting code.

The C11 language, with minimal support for lex(1), yacc(1) and Objective-C input. Inferred for *.[chlmy] files.
BSD make(1). Inferred for Makefile, *.mk and *.am files.
The mdoc(7) language. Inferred for *.[1-9] files and files starting with “.Dd”.
POSIX sh(1). Since lexical analysis of the shell command language is effectively impossible, this is best-effort only. Inferred for *.sh, .profile, .shrc files and files starting with “#!/bin/sh”.
Plain text. Inferred for *.txt files.

The command to pipe ANSI output to if standard output is a terminal. The default is PAGER=less.
January 20, 2021 OpenBSD 7.3

hilex.c in git 

/* Copyright (C) 2020  June McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <regex.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <sysexits.h>
#include <unistd.h>

#include "hilex.h"

#define ARRAY_LEN(a) (sizeof(a) / sizeof(a[0]))

static const char *Class[] = {
#define X(class) [class] = #class,
	ENUM_CLASS
#undef X
};

static FILE *yyin;
static char *yytext;
static int yylex(void) {
	static size_t cap = 0;
	return (getline(&yytext, &cap, yyin) < 0 ? None : Normal);
}
static const struct Lexer LexText = { yylex, &yyin, &yytext };

static const struct {
	const struct Lexer *lexer;
	const char *name;
	const char *namePatt;
	const char *linePatt;
} Lexers[] = {
	{ &LexC, "c", "[.][chlmy]$", NULL },
	{ &LexMake, "make", "[.](mk|am)$|^Makefile$", NULL },
	{ &LexMdoc, "mdoc", "[.][1-9]$", "^[.]Dd" },
	{ &LexSh, "sh", "[.]sh$|^[.](profile|shrc)$", "^#![ ]?/bin/k?sh" },
	{ &LexText, "text", "[.]txt$", NULL },
};

static const struct Lexer *parseLexer(const char *name) {
	for (size_t i = 0; i < ARRAY_LEN(Lexers); ++i) {
		if (!strcmp(name, Lexers[i].name)) return Lexers[i].lexer;
	}
	errx(EX_USAGE, "unknown lexer %s", name);
}

static void ungets(const char *str, FILE *file) {
	size_t len = strlen(str);
	for (size_t i = len-1; i < len; --i) {
		int ch = ungetc(str[i], file);
		if (ch == EOF) errx(EX_IOERR, "cannot push back string");
	}
}

static const struct Lexer *matchLexer(const char *name, FILE *file) {
	char buf[256];
	regex_t regex;
	for (size_t i = 0; i < ARRAY_LEN(Lexers); ++i) {
		int error = regcomp(
			&regex, Lexers[i].namePatt, REG_EXTENDED | REG_NOSUB
		);
		assert(!error);
		error = regexec(&regex, name, 0, NULL, 0);
		regfree(&regex);
		if (!error) return Lexers[i].lexer;
	}
	char *line = fgets(buf, sizeof(buf), file);
	if (!line) return NULL;
	for (size_t i = 0; i < ARRAY_LEN(Lexers); ++i) {
		if (!Lexers[i].linePatt) continue;
		int error = regcomp(
			&regex, Lexers[i].linePatt, REG_EXTENDED | REG_NOSUB
		);
		assert(!error);
		error = regexec(&regex, line, 0, NULL, 0);
		regfree(&regex);
		if (!error) {
			ungets(line, file);
			return Lexers[i].lexer;
		}
	}
	ungets(line, file);
	return NULL;
}

#define ENUM_OPTION \
	X(Document, "document") \
	X(Inline, "inline") \
	X(Monospace, "monospace") \
	X(Pre, "pre") \
	X(Style, "style") \
	X(Tab, "tab") \
	X(Title, "title")

enum Option {
#define X(option, key) option,
	ENUM_OPTION
#undef X
	OptionCap,
};

typedef void Header(const char *opts[]);
typedef void Output(const char *opts[], enum Class class, const char *text);

static bool pager;
static void ansiHeader(const char *opts[]) {
	(void)opts;
	if (!pager) return;
	const char *shell = getenv("SHELL");
	const char *pager = getenv("PAGER");
	if (!shell) shell = "/bin/sh";
	if (!pager) pager = "less";
	setenv("LESS", "FRX", 0);

	int rw[2];
	int error = pipe(rw);
	if (error) err(EX_OSERR, "pipe");

	pid_t pid = fork();
	if (pid < 0) err(EX_OSERR, "fork");
	if (!pid) {
		dup2(rw[0], STDIN_FILENO);
		close(rw[0]);
		close(rw[1]);
		execl(shell, shell, "-c", pager, NULL);
		err(EX_CONFIG, "%s", shell);
	}
	dup2(rw[1], STDOUT_FILENO);
	close(rw[0]);
	close(rw[1]);
	setlinebuf(stdout);

#ifdef __OpenBSD__
	error = pledge("stdio", NULL);
	if (error) err(EX_OSERR, "pledge");
#endif
}

static void ansiFooter(const char *opts[]) {
	(void)opts;
	if (!pager) return;
	int status;
	fclose(stdout);
	wait(&status);
}

static const char *SGR[ClassCap] = {
	[Keyword] = "37",
	[Macro]   = "32",
	[Comment] = "34",
	[String]  = "36",
	[Format]  = "36;1;96",
	[Subst]   = "33",
};

static void ansiFormat(const char *opts[], enum Class class, const char *text) {
	(void)opts;
	if (!SGR[class]) {
		printf("%s", text);
		return;
	}
	// Set color on each line for piping to less -R:
	for (const char *nl; (nl = strchr(text, '\n')); text = &nl[1]) {
		printf("\33[%sm%.*s\33[m\n", SGR[class], (int)(nl - text), text);
	}
	if (*text) printf("\33[%sm%s\33[m", SGR[class], text);
}

static void
debugFormat(const char *opts[], enum Class class, const char *text) {
	if (class != Normal) {
		printf("%s(", Class[class]);
		ansiFormat(opts, class, text);
		printf(")");
	} else {
		printf("%s", text);
	}
}

static const char *IRC[ClassCap] = {
	[Keyword] = "\00315",
	[Macro]   = "\0033",
	[Comment] = "\0032",
	[String]  = "\00310",
	[Format]  = "\00311",
	[Subst]   = "\0037",
};

static void ircHeader(const char *opts[]) {
	if (opts[Monospace]) printf("\21");
}

static const char *stop(const char *text) {
	return (*text == ',' || isdigit(*text) ? "\2\2" : "");
}

static void ircFormat(const char *opts[], enum Class class, const char *text) {
	for (const char *nl; (nl = strchr(text, '\n')); text = &nl[1]) {
		if (IRC[class]) printf("%s%s", IRC[class], stop(text));
		printf("%.*s\n", (int)(nl - text), text);
		if (opts[Monospace]) printf("\21");
	}
	if (*text) {
		if (IRC[class]) {
			printf("%s%s%s\17", IRC[class], stop(text), text);
			if (opts[Monospace]) printf("\21");
		} else {
			printf("%s", text);
		}
	}
}

static void htmlEscape(const char *text) {
	while (*text) {
		switch (*text) {
			break; case '"': text++; printf("&quot;");
			break; case '&': text++; printf("&amp;");
			break; case '<': text++; printf("&lt;");
		}
		size_t len = strcspn(text, "\"&<");
		if (len) fwrite(text, len, 1, stdout);
		text += len;
	}
}

static const char *Styles[ClassCap] = {
	[Keyword] = "color: dimgray;",
	[Macro]   = "color: green;",
	[Comment] = "color: navy;",
	[String]  = "color: teal;",
	[Format]  = "color: teal; font-weight: bold;",
	[Subst]   = "color: olive;",
};

static void styleTabSize(const char *tab) {
	printf("-moz-tab-size: ");
	htmlEscape(tab);
	printf("; tab-size: ");
	htmlEscape(tab);
	printf(";");
}

static void htmlHeader(const char *opts[]) {
	if (!opts[Document]) goto body;

	printf("<!DOCTYPE html>\n<title>");
	if (opts[Title]) htmlEscape(opts[Title]);
	printf("</title>\n");

	if (opts[Style]) {
		printf("<link rel=\"stylesheet\" href=\"");
		htmlEscape(opts[Style]);
		printf("\">\n");
	} else if (!opts[Inline]) {
		printf("<style>\n");
		if (opts[Tab]) {
			printf("pre.hilex { ");
			styleTabSize(opts[Tab]);
			printf(" }\n");
		}
		for (enum Class class = 0; class < ClassCap; ++class) {
			if (!Styles[class]) continue;
			printf("pre.hilex .%.2s { %s }\n", Class[class], Styles[class]);
		}
		printf("</style>\n");
	}

body:
	if ((opts[Document] || opts[Pre]) && opts[Inline] && opts[Tab]) {
		printf("<pre class=\"hilex\" style=\"");
		styleTabSize(opts[Tab]);
		printf("\">");
	} else if (opts[Document] || opts[Pre]) {
		printf("<pre class=\"hilex\">");
	}
}

static void htmlFooter(const char *opts[]) {
	if (opts[Document] || opts[Pre]) printf("</pre>");
	if (opts[Document]) printf("\n");
}

static void htmlFormat(const char *opts[], enum Class class, const char *text) {
	if (class != Normal) {
		if (opts[Inline]) {
			printf("<span style=\"%s\">", Styles[class] ? Styles[class] : "");
		} else {
			printf("<span class=\"%.2s\">", Class[class]);
		}
		htmlEscape(text);
		printf("</span>");
	} else {
		htmlEscape(text);
	}
}

static const struct Formatter {
	const char *name;
	Header *header;
	Output *format;
	Header *footer;
} Formatters[] = {
	{ "ansi", ansiHeader, ansiFormat, ansiFooter },
	{ "debug", NULL, debugFormat, NULL },
	{ "html", htmlHeader, htmlFormat, htmlFooter },
	{ "irc", ircHeader, ircFormat, NULL },
};

static const struct Formatter *parseFormatter(const char *name) {
	for (size_t i = 0; i < ARRAY_LEN(Formatters); ++i) {
		if (!strcmp(name, Formatters[i].name)) return &Formatters[i];
	}
	errx(EX_USAGE, "unknown formatter %s", name);
}

static char *const OptionKeys[OptionCap + 1] = {
#define X(option, key) [option] = key,
	ENUM_OPTION
#undef X
	NULL,
};

int main(int argc, char *argv[]) {
	bool text = false;
	const char *name = NULL;
	const struct Lexer *lexer = NULL;
	const struct Formatter *formatter = &Formatters[0];
	const char *opts[OptionCap] = {0};

	for (int opt; 0 < (opt = getopt(argc, argv, "f:l:n:o:t"));) {
		switch (opt) {
			break; case 'f': formatter = parseFormatter(optarg);
			break; case 'l': lexer = parseLexer(optarg);
			break; case 'n': name = optarg;
			break; case 'o': {
				while (*optarg) {
					char *val;
					int key = getsubopt(&optarg, OptionKeys, &val);
					if (key < 0) errx(EX_USAGE, "no such option %s", val);
					opts[key] = (val ? val : "");
				}
			}
			break; case 't': text = true;
			break; default:  return EX_USAGE;
		}
	}

	const char *path = "(stdin)";
	FILE *file = stdin;
	if (optind < argc) {
		path = argv[optind];
		file = fopen(path, "r");
		if (!file) err(EX_NOINPUT, "%s", path);
		pager = isatty(STDOUT_FILENO);
	}

#ifdef __OpenBSD__
	int error;
	if (formatter->header == ansiHeader && pager) {
		error = pledge("stdio proc exec", NULL);
	} else {
		error = pledge("stdio", NULL);
	}
	if (error) err(EX_OSERR, "pledge");
#endif

	if (!name) {
		if (NULL != (name = strrchr(path, '/'))) {
			name++;
		} else {
			name = path;
		}
	}
	if (!opts[Title]) opts[Title] = name;
	if (!lexer) lexer = matchLexer(name, file);
	if (!lexer && text) lexer = &LexText;
	if (!lexer) errx(EX_USAGE, "cannot infer lexer for %s", name);

	*lexer->in = file;
	if (formatter->header) formatter->header(opts);
	for (enum Class class; None != (class = lexer->lex());) {
		assert(class < ClassCap);
		formatter->format(opts, class, *lexer->text);
	}
	if (formatter->footer) formatter->footer(opts);
}