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| author | bptato <nincsnevem662@gmail.com> | 2023-12-10 17:15:18 +0100 |
|---|---|---|
| committer | bptato <nincsnevem662@gmail.com> | 2023-12-10 17:29:41 +0100 |
| commit | 48b197133783bf7ec7211b1e114b6ca73f36a3c6 (patch) | |
| tree | b1bbc4ddec8791022f04b11587c1aee3c7b1656a /adapter | |
| parent | 2dec7483045c9e5696182db7b4ad842491b6c2b2 (diff) | |
| download | chawan-48b197133783bf7ec7211b1e114b6ca73f36a3c6.tar.gz | |
Separate gopher conversion from main binary
Now we use a (much simplified) gopher2html binary in libexec, instead of converting gopher directories to HTML in loader/gopher. This has two advantages: * Less ugly conversion logic in the loader module; we can just convert the file line by line. (The previous converter also had some correctness issues, that is fixed now as well.) * If the user desires, they can replace the gopher converter with another binary using the mailcap mechanism. The disadvantages are: * For now, source display is broken. This is a problem with all mailcap filters in general, and should be fixed in the future. (That said, the previous version also only displayed the converted HTML source, which was not really useful anyway.) * The proper directory structure is required for this to work; OTOH plenty of work has been done so that this is as frictionless as possible, so it should not really be a problem.
Diffstat (limited to 'adapter')
| -rw-r--r-- | adapter/gopher/gopher2html.nim | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/adapter/gopher/gopher2html.nim b/adapter/gopher/gopher2html.nim new file mode 100644 index 00000000..4821814f --- /dev/null +++ b/adapter/gopher/gopher2html.nim @@ -0,0 +1,149 @@ +# This file is dedicated to the public domain. +# Gopher directory -> HTML converter for Chawan. + +import std/os +import std/streams +import std/strutils + +type GopherType = enum + UNKNOWN = "unsupported" + TEXT_FILE = "text file" + ERROR = "error" + DIRECTORY = "directory" + DOS_BINARY = "DOS binary" + SEARCH = "search" + MESSAGE = "message" + SOUND = "sound" + GIF = "gif" + HTML = "HTML" + INFO = "" + IMAGE = "image" + BINARY = "binary" + PNG = "png" + +func gopherType(c: char): GopherType = + return case c + of '0': TEXT_FILE + of '1': DIRECTORY + of '3': ERROR + of '5': DOS_BINARY + of '7': SEARCH + of 'm': MESSAGE + of 's': SOUND + of 'g': GIF + of 'h': HTML + of 'i': INFO + of 'I': IMAGE + of '9': BINARY + of 'p': PNG + else: UNKNOWN + +func htmlEscape(s: string): string = + result = "" + for c in s: + case c + of '<': result &= "<" + of '>': result &= ">" + of '&': result &= "&" + of '"': result &= """ + of '\'': result &= "'" + else: result &= c + +func until(s: string, c: char, starti = 0): string = + for i in starti ..< s.len: + if s[i] == c: + break + result &= s[i] + +const ControlPercentEncodeSet = {char(0x00)..char(0x1F), char(0x7F)..char(0xFF)} +const QueryPercentEncodeSet = (ControlPercentEncodeSet + {' ', '"', '#', '<', '>'}) +const PathPercentEncodeSet = (QueryPercentEncodeSet + {'?', '`', '{', '}'}) +const HexCharsUpper = "0123456789ABCDEF" +proc percentEncode(s: string): string = + result = "" + for c in s: + if c notin PathPercentEncodeSet: + result &= c + else: + result &= '%' + result &= HexCharsUpper[uint8(c) shr 4] + result &= HexCharsUpper[uint8(c) and 0xF] + +# returns URL +proc parseParams(): string = + result = "" + let params = commandLineParams() + var was_u = false + for param in params: + if was_u: + result = param + was_u = false + elif param == "-h" or param == "--help": + stdout.write("Usage: gopher2html [-u URL]") + quit(0) + elif param == "-u": + was_u = true + else: + stdout.write("Usage: gopher2html [-u URL]") + quit(1) + +proc main() = + let url = parseParams() + let escapedURL = htmlEscape(url) + stdout.write(""" +<!DOCTYPE HTML> +<HTML> +<HEAD> +<BASE HREF="""" & url & """"> +<TITLE>Index of """ & escapedURL & """</TITLE> +</HEAD> +<BODY> +<H1>Index of """ & escapedURL & """</H1>""") + let ins = newFileStream(stdin) + var ispre = false + while not ins.atEnd: + let line = ins.readLine() + if line.len == 0: + break # invalid + let tc = line[0] + if tc == '.': + break # end + var i = 1 + template get_field(): string = + let s = line.until('\t', i) + i += s.len + if i >= line.len or line[i] != '\t': + break # invalid + inc i + s + let t = gopherType(tc) + let name = get_field() + var file = get_field() + let host = get_field() + let port = line.until('\t', i) # ignore anything after port + var outs = "" + if t == INFO: + if not ispre: + outs &= "<PRE>" + ispre = true + outs &= htmlEscape(name) & '\n' + else: + if ispre: + outs &= "</PRE>" + ispre = false + let ts = $t + var names = "" + if ts != "": + names &= '[' & ts & ']' + names &= htmlEscape(name) + let ourls = if not file.startsWith("URL:"): + if file.len == 0 or file[0] != '/': + file = '/' & file + let pefile = percentEncode(file) + "gopher://" & host & ":" & port & "/" & tc & pefile + else: + file.substr("URL:".len) + outs &= "<A HREF=\"" & htmlEscape(ourls) & "\">" & names & "</A><BR>\n" + stdout.write(outs) + +main() |