firefox_profile_relax_github_stackexchange_column_width.sh

echo {} /* >/dev/null SG\MARKER\VERY\IMPROBABLE\STRING\MY\START

# This file is both a valid CSS style sheet,
# and a valid bash script.

# It adjusts your main Firefox profile so that github and all the
# stackexchange websites do not artifically limit main area width.
# Hooray! No more clobbered listings!

# More technically, it configures and enables userContent.css.  It
# will preserve pre-existing content of that file and add itself at
# the beginning.

# You can even run it again in your profile directory to update the
# list of stackexchange websites:

# bash firefox_profile_relax_github_stackexchange_column_width.sh

# It requires curl and basic POSIX tools.  May not work on BSD and thus Mac OS X but should be relatively easy to fix.

# If you don't have realpath or readlink, you may get a portable
# variant on
# https://github.com/mkropat/sh-realpath/blob/master/realpath.sh

set -eu

THIS_FILE="${BASH_SOURCE[0]}"

# find_firefox_profile()
{
    # Based on https://askubuntu.com/questions/239543/get-the-default-firefox-profile-directory-from-bash
    cd ~/.mozilla/firefox/ && if [[ $(grep '\[Profile[^0]\]' profiles.ini) ]]
    then FFPROFILE="$PWD/$(sed -E -n '/^Default=/{s/^Default=(.*)$/\1/p;q}' profiles.ini)"
    else FFPROFILE="$PWD/$(grep 'Path=' profiles.ini | sed 's/^Path=//')"
    fi
    cd "$OLDPWD"
}

echo >&2 "Firefox profile found in: ${FFPROFILE}"

[[ -d "${FFPROFILE}/chrome" ]] || mkdir "${FFPROFILE}/chrome"

TARGET="${FFPROFILE}/chrome/userContent.css"

ALL_STACKEXCHANGE_DOMAINS=""

while read -u 4 DOMAIN
do
    ALL_STACKEXCHANGE_DOMAINS="$ALL_STACKEXCHANGE_DOMAINS domain($DOMAIN),"
done 4< <( if ! [[ -r stackexchange_sites.html ]]
           then curl https://stackexchange.com/sites >|stackexchange_sites.html
           fi
           sed <stackexchange_sites.html -n 's|^.*<a href="https://\([^"]*\)" class="noscript-link.*$|\1|p' )
ALL_STACKEXCHANGE_DOMAINS="$ALL_STACKEXCHANGE_DOMAINS domain\(SG_MARKER_VERY_IMPROBABLE_STRING_ALLSTACKEXCHANGEDOMAINS\)"
{
    # Insert our part first.
    sed '/SG\\MARKER\\VERY\\IMPROBABLE\\STRING\\BASH\\START/,/SG\\MARKER\\VERY\\IMPROBABLE\\STRING\\BASH\\END/d' <"${THIS_FILE}" |
        sed -E "s/^.*\(SG_MARKER_VERY_IMPROBABLE_STRING_ALLSTACKEXCHANGEDOMAINS\)$/@-moz-document $ALL_STACKEXCHANGE_DOMAINS/"

    # Preserve original file content, removing all our part.
    [[ -f "${TARGET}" ]] && sed  '/SG\\MARKER\\VERY\\IMPROBABLE\\STRING\\MY\\START/,/SG\\MARKER\\VERY\\IMPROBABLE\\STRING\\MY\\END/d' <"${TARGET}"
} > ${TARGET}.tmp

mv -vf ${TARGET}.tmp ${TARGET}

echo 'user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true);' >>"${FFPROFILE}/prefs.js"

# If firefox is active, the customzation above will be lost when it closes.

if [[ -L "${FFPROFILE}/lock" ]]
then
    # Yes, there is a race condition.  Let's accept is on the basis of
    # the Buridan's_principle
    # https://en.wikipedia.org/wiki/Buridan's_ass#Buridan's_principle
    echo -n >&2 "Warning: firefox appears to be active.  Waiting of it to stop."
    while [[ -L "${FFPROFILE}/lock" ]]
    do
        echo >&2 -n .
        sleep 1
    done
    echo >&2 "Okay!"
fi

echo 'user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true);' >>"${FFPROFILE}/prefs.js"

echo >&2 "Firefox profile configured to honor userContent.css."

exit 0

Bash ended. Now switch to CSS part.

SG\MARKER\VERY\IMPROBABLE\STRING\BASH\END */

@namespace url(http://www.w3.org/1999/xhtml);

/* Don't limit width on github.com */
@-moz-document domain(github.com)
{
    .container-lg {
        max-width: 100% !important;
    }
}

/* Don't limit width on StackExchange sites. */
@-moz-document domain(SG_MARKER_VERY_IMPROBABLE_STRING_ALLSTACKEXCHANGEDOMAINS)
{
    #content {
        max-width: 100% !important;
        width: 100% !important;
    }
    #content {
        width: 100% !important;
    }
    body > .container {
        max-width: 100% !important;
    }
}

/* SG\MARKER\VERY\IMPROBABLE\STRING\MY\END */