It works!

1 files changed, 209 insertions, 161 deletions

@@ -1,191 +1,239 @@
-#!/bin/bash
-# bollux: bash gemini client
+#!/usr/bin/env bash
+# bollux: a bash gemini client or whatever
 # Author: Case Duckworth <acdw@acdw.net>
 # License: MIT
-# Version: -1
+# Version: -0.8
 
-PRGN="${0##*/}"
+set -euo pipefail
 
-main() {
-        if [[ -z "$1" ]]; then
-                echo "usage: $PRGN <URL>"
-                return 1
-        fi
+### constants ###
+PRGN="${0##*/}"                # program name
+PROT="${BOLLUX_PROTO:-gemini}" # protocol
+PORT="${BOLLUX_PORT:-1965}"    # port number
+LOGL="${BOLLUX_LOGLEVEL:-3}"   # log level
+MAXR="${BOLLUX_MAXREDIR:-5}"   # max redirects
+RDRS=0                         # redirects
+
+# LOGLEVELS:
+# 0 - application fatal error
+# 1 - application warning
+# 2 - response error
+# 3 - response logging
+# 4 - application logging
+# 5 - diagnostic
+
+### utility functions ###
+# a better echo
+put() { printf '%s\n' "$*"; }
 
-        log "$PRGN $*"
-        log address="$(address "$1"|tr '[:space:]' 'x')"
-        log server="$(server "$1")"
+# conditionally log events to stderr
+# lower = more important
+log() { # log [LEVEL] [<] MESSAGE
+        case "$1" in
+        [0-5])
+                lvl="$1"
+                shift
+                ;;
+        *) lvl=4 ;;
+        esac
 
-        address "$1" |
-                download "$(server "$1")" 2>/dev/null |
-                handle_status "$1"
+        output="$*"
+        if ((lvl < LOGL)); then
+                if (($# == 0)); then
+                        while IFS= read -r line; do
+                                output="$output${output:+$'\n'}$line"
+                        done
+                fi
+                printf '\e[3%dm%s\e[0m:\t%s\n' "$((lvl + 1))" "$PRGN" "$output" >&2
+        fi
 }
 
-log() {
-        printf '\e[34m%s:\t%s\e[0m\n' "$PRGN" "$*" >&2
+# halt and catch fire
+die() { # die [EXIT-CODE] MESSAGE
+        case "$1" in
+        [0-9]*)
+                ec="$1"
+                shift
+                ;;
+        *) ec=1 ;;
+        esac
+
+        log 0 "$*"
+        exit "$ec"
 }
 
-address() {
-        local addr="$1"
-        if [[ "$addr" != gemini://* ]]; then
-                addr="gemini://$addr"
-        fi
-        echo "$addr" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'
+# fail if something isn't installed
+require() { hash "$1" 2>/dev/null || die 127 "Requirement '$1' not found."; }
+
+# trim a string
+trim() { sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'; }
+
+# stubs for when things aren't implemented (fully)
+NOT_IMPLEMENTED() { die 200 "NOT IMPLEMENTED!!!"; }
+NOT_FULLY_IMPLEMENTED() { log 1 "NOT FULLY IMPLEMENTED!!!"; }
+
+### gemini ###
+# normalize a gemini address
+# example.com => gemini://example.com/
+_address() { # _address URL
+        addr="$1"
+        [[ "$addr" != *://* ]] && addr="$PROT://$addr"
+        trim <<<"$addr"
 }
 
-server() {
-        local serv="${1#*://}"
+# return only the server part from an address, with the port added
+# gemini://example.com/path/to/file => example.com:1965
+_server() {
+        serv="$(_address "$1")" # normalize first
+        serv="${serv#*://}"
         serv="${serv%%/*}"
-        if [[ ! "$serv" = *:* ]]; then
-                serv="$serv:1965"
+        if [[ "$serv" != *:* ]]; then
+                serv="$serv:$PORT"
         fi
-        echo "$serv"
+        trim <<<"$serv"
 }
 
-download() {
-        openssl s_client -crlf -ign_eof -quiet -connect "$1"
-}
+# request a gemini page
+# by default, extract the server from the url
+request() { # request [-s SERVER] URL
+        case "$1" in
+        -s)
+                serv="$(_server "$2")"
+                addr="$(_address "$3")"
+                ;;
+        *)
+                serv="$(_server "$1")"
+                addr="$(_address "$1")"
+                ;;
+        esac
 
-display() {
-        addr="$(address "$1")"
-        printf '        🚀 %s 🚀\n' "$addr"
-        echo
-        cat
-        printf '        🚀 END: %s 🚀\n' "$addr"
-}
+        log 5 "serv: $serv"
+        log 5 "addr: $addr"
 
-NOT_IMPLEMENTED() {
-        log "NOT IMPLEMENTED!!!" >&2
-        exit 127
-}
-NOT_FULLY_IMPLEMENTED() {
-        log "NOT FULLY IMPLEMENTED!!!" >&2
+        t="$(mktemp)"
+
+        sslcmd=(openssl s_client -crlf -ign_eof -quiet -connect "$serv")
+        log "${sslcmd[@]}"
+        "${sslcmd[@]}" <<<"$addr" 2>"$t"
+
+        ((LOGL > 4)) && cat "$t"
+        rm "$t"
 }
 
-handle_status() {
-        # cf. https://gemini.circumlunar.space/docs/spec-spec.txt
-        addr="$(address "$1")"
-        IN="$(cat)"
-        head="$(head -n1 <<<"$IN")"
-        stat="$(awk '{print $1}' <<<"$head")"
-        msg="$(awk '{for(i=2;i<=NF;i++)printf "%s ", $i;printf "\n";}' <<<"$head")"
-        log "$stat      $msg"
-        case "$stat" in
-        10) # INPUT
-                #       As per definition of single-digit code 1 in 1.3.2.
-                NOT_IMPLEMENTED
-                ;;
-        20) # SUCCESS
-                #       As per definition of single-digit code 2 in 1.3.2.
-                display "$addr" <<<"$IN"
+# handle the response
+# cf. gemini://gemini.circumlunar.space/docs/spec-spec.txt
+handle() { # handle URL < RESPONSE
+        url="$(_address "$1")"
+        resp="$(cat)"
+        head="$(sed 1q <<<"$resp")"
+        body="$(sed 1d <<<"$resp")"
+
+        code="$(awk '{print $1}' <<<"$head")"
+        meta="$(awk '{for(i=2;i<=NF;i++)printf "%s ",$i;printf "\n"}' <<<"$head")"
+
+        log 5 "[$code]  $meta"
+
+        case "$code" in
+        1*) # INPUT
+                log 3 "Input"
+                put "$meta"
+                read -rep "? "
+                bollux "$url?$REPLY"
                 ;;
-        21) # SUCCESS - END OF CLIENT CERTIFICATE SESSION
-                #       The request was handled successfully and a response body will
-                #       follow the response header.  The <META> line is a MIME media
-                #       type which applies to the response body.  In addition, the
-                #       server is signalling the end of a transient client certificate
-                #       session which was previously initiated with a status 61
-                #       response.  The client should immediately and permanently
-                #       delete the certificate and accompanying private key which was
-                #       used in this request.
-                display "$addr" <<<"$IN"
-                NOT_FULLY_IMPLEMENTED
+        2*) # SUCCESS
+                log 3 "Success"
+                case "$code" in
+                20) log 5 "- OK" ;;
+                21) log 5 "- End of client certificate session" ;;
+                *) log 2 "- Unknown response code: '$code'." ;;
+                esac
+                display <<<"$body"
                 ;;
-        30) # REDIRECT - TEMPORARY
-                #       As per definition of single-digit code 3 in 1.3.2.
-                exec "$0" "$msg"
+        3*) # REDIRECT
+                log 3 "Redirecting"
+                case "$code" in
+                30) log 5 "- Temporary" ;;
+                31) log 5 "- Permanent" ;;
+                *) log 2 "- Unknown response code: '$code'." ;;
+                esac
+                ((RDRS+=1))
+                ((RDRS > MAXR)) && die "$code" "Too many redirects!"
+                bollux "$meta"
                 ;;
-        31) # REDIRECT - PERMANENT
-                #       The requested resource should be consistently requested from
-                #       the new URL provided in future.  Tools like search engine
-                #       indexers or content aggregators should update their
-                #       configurations to avoid requesting the old URL, and end-user
-                #       clients may automatically update bookmarks, etc.  Note that
-                #       clients which only pay attention to the initial digit of
-                #       status codes will treat this as a temporary redirect.  They
-                #       will still end up at the right place, they just won't be able
-                #       to make use of the knowledge that this redirect is permanent,
-                #       so they'll pay a small performance penalty by having to follow
-                #       the redirect each time.
-                exec "$0" "$msg"
-                NOT_FULLY_IMPLEMENTED
+        4*) # TEMPORARY FAILURE
+                log 2 "Temporary failure"
+                case "$code" in
+                41) log 5 "- Server unavailable" ;;
+                42) log 5 "- CGI error" ;;
+                43) log 5 "- Proxy error" ;;
+                44) log 5 "- Rate limited" ;;
+                *) log 2 "- Unknown response code: '$code'." ;;
+                esac
+                exit "$code"
                 ;;
-        4*) # 40 - TEMPORARY FAILURE
-                #       As per definition of single-digit code 4 in 1.3.2.
-                # 41 - SERVER UNAVAILABLE
-                #       The server is unavailable due to overload or maintenance.
-                #       (cf HTTP 503)
-                # 42 - CGI ERROR
-                #       A CGI process, or similar system for generating dynamic
-                #       content, died unexpectedly or timed out.
-                # 43 - PROXY ERROR
-                #       A proxy request failed because the server was unable to
-                #       successfully complete a transaction with the remote host.
-                #       (cf HTTP 502, 504)
-                # 44 - SLOW DOWN
-                #       Rate limiting is in effect.  <META> is an integer number of
-                #       seconds which the client must wait before another request is
-                #       made to this server.
-                #       (cf HTTP 429)
-                printf 'OH SHIT!\n%s\t%s\n' "$stat" "$msg" | display "$addr"
-                NOT_FULLY_IMPLEMENTED
+        5*) # PERMANENT FAILURE
+                log 2 "Permanent failure"
+                case "$code" in
+                51) log 5 "- Not found" ;;
+                52) log 5 "- No longer available" ;;
+                53) log 5 "- Proxy request refused" ;;
+                59) log 5 "- Bad request" ;;
+                *) log 2 "- Unknown response code: '$code'." ;;
+                esac
+                exit "$code"
                 ;;
-        5*) # 50 - PERMANENT FAILURE
-                #       As per definition of single-digit code 5 in 1.3.2.
-                # 51 - NOT FOUND
-                #       The requested resource could not be found but may be available
-                #       in the future.
-                #       (cf HTTP 404)
-                #       (struggling to remember this important status code?  Easy:
-                #       you can't find things hidden at Area 51!)
-                # 52 - GONE
-                #       The resource requested is no longer available and will not be
-                #       available again.  Search engines and similar tools should
-                #       remove this resource from their indices.  Content aggregators
-                #       should stop requesting the resource and convey to their human
-                #       users that the subscribed resource is gone.
-                #       (cf HTTP 410)
-                # 53 - PROXY REQUEST REFUSED
-                #       The request was for a resource at a domain not served by the
-                #       server and the server does not accept proxy requests.
-                # 59 - BAD REQUEST
-                #       The server was unable to parse the client's request,
-                #       presumably due to a malformed request.
-                #       (cf HTTP 400)
-                printf 'OH SHIT!\n%s\t%s\n' "$stat" "$msg" | display "$addr"
-                NOT_FULLY_IMPLEMENTED
+        6*) # CLIENT CERT REQUIRED
+                log 2 "Client certificate required"
+                case "$code" in
+                61) log 5 "- Transient cert requested" ;;
+                62) log 5 "- Authorized cert required" ;;
+                63) log 5 "- Cert not accepted" ;;
+                64) log 5 "- Future cert rejected" ;;
+                65) log 5 "- Expired cert rejected" ;;
+                *) log 2 "- Unknown response code: '$code'." ;;
+                esac
+                exit "$code"
                 ;;
-        6*) # 60 - CLIENT CERTIFICATE REQUIRED
-                #       As per definition of single-digit code 6 in 1.3.2.
-                # 61 - TRANSIENT CERTIFICATE REQUESTED
-                #       The server is requesting the initiation of a transient client
-                #       certificate session, as described in 1.4.3.  The client should
-                #       ask the user if they want to accept this and, if so, generate
-                #       a disposable key/cert pair and re-request the resource using it.
-                #       The key/cert pair should be destroyed when the client quits,
-                #       or some reasonable time after it was last used (24 hours?
-                #       Less?)
-                # 62 - AUTHORISED CERTIFICATE REQUIRED
-                #       This resource is protected and a client certificate which the
-                #       server accepts as valid must be used - a disposable key/cert
-                #       generated on the fly in response to this status is not
-                #       appropriate as the server will do something like compare the
-                #       certificate fingerprint against a white-list of allowed
-                #       certificates.  The client should ask the user if they want to
-                #       use a pre-existing certificate from a stored "key chain".
-                # 63 - CERTIFICATE NOT ACCEPTED
-                #       The supplied client certificate is not valid for accessing the
-                #       requested resource.
-                # 64 - FUTURE CERTIFICATE REJECTED
-                #       The supplied client certificate was not accepted because its
-                #       validity start date is in the future.
-                # 65 - EXPIRED CERTIFICTE REJECTED
-                #       The supplied client certificate was not accepted because its
-                #       expiry date has passed.
-                printf 'OH SHIT!\n%s\t%s\n' "$stat" "$msg" | display "$addr"
-                NOT_FULLY_IMPLEMENTED
+        *) # ???
+                die "$code" "Unknown response code: '$code'."
                 ;;
         esac
 }
 
-main "$@"
+# display the page
+display() { # display <<< STRING
+        cat
+        # TODO: use less with linking and stuff
+        # less -R -p'^=>' +g
+        # lesskey:
+        # l /=>\n # highlight links
+        # o pipe \n open_url # open the link on the top line
+        # u shell select_url % # shows a selection prompt for all urls (on screen? file?)
+        # Q exit 1  # for one of these, show a selection prompt for urls
+        # q exit 0  # for the other, just quit
+        ###
+        # also look into the prompt, the filename, and input preprocessor
+        # ($LESSOPEN, $LESSCLOSE)
+}
+
+### main entry point ###
+bollux() {
+        if (($# == 1)); then
+                url="$1"
+        else
+                read -rp "GO> " url
+        fi
+
+        log 5 "url : $url"
+        log 5 "addr: $(_address "$url")"
+        log 5 "serv: $(_server "$url")"
+
+        request "$url" | handle "$url"
+}
+
+if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
+        # requirements here -- so they're only checked once
+        require openssl
+
+        bollux "$@"
+fi