<h2>Editing File: /lib/dracut/dracut-logger.sh</h2><form method='post'><textarea name='content' class='file-edit'>#!/bin/bash
#
# logging faciality module for dracut both at build- and boot-time
#
# Copyright 2010 Amadeusz Żołnowski &lt;aidecoe@aidecoe.name&gt;
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see &lt;http://www.gnu.org/licenses/&gt;.


__DRACUT_LOGGER__=1


## @brief Logging facility module for dracut both at build- and boot-time.
#
# @section intro Introduction
#
# The logger takes a bit from Log4j philosophy. There are defined 6 logging
# levels:
#   - TRACE (6)
#     The TRACE Level designates finer-grained informational events than the
#     DEBUG.
#   - DEBUG (5)
#     The DEBUG Level designates fine-grained informational events that are most
#     useful to debug an application.
#   - INFO (4)
#     The INFO level designates informational messages that highlight the
#     progress of the application at coarse-grained level.
#   - WARN (3)
#     The WARN level designates potentially harmful situations.
#   - ERROR (2)
#     The ERROR level designates error events that might still allow the
#     application to continue running.
#   - FATAL (1)
#     The FATAL level designates very severe error events that will presumably
#     lead the application to abort.
# Descriptions are borrowed from Log4j documentation:
# http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html
#
# @section usage Usage
#
# First of all you have to start with dlog_init() function which initializes
# required variables. Don't call any other logging function before that one!
# If you're ready with this, you can use following functions which corresponds
# clearly to levels listed in @ref intro Introduction. Here they are:
#   - dtrace()
#   - ddebug()
#   - dinfo()
#   - dwarn()
#   - derror()
#   - dfatal()
# They take all arguments given as a single message to be logged. See dlog()
# function for details how it works. Note that you shouldn't use dlog() by
# yourself. It's wrapped with above functions.
#
# @see dlog_init() dlog()
#
# @section conf Configuration
#
# Logging is controlled by following global variables:
#   - @var stdloglvl - logging level to standard error (console output)
#   - @var sysloglvl - logging level to syslog (by logger command)
#   - @var fileloglvl - logging level to file
#   - @var kmsgloglvl - logging level to /dev/kmsg (only for boot-time)
#   - @var logfile - log file which is used when @var fileloglvl is higher
#   than 0
# and two global variables: @var maxloglvl and @var syslogfacility which &lt;b&gt;must
# not&lt;/b&gt; be overwritten. Both are set by dlog_init(). @var maxloglvl holds
# maximum logging level of those three and indicates that dlog_init() was run.
# @var syslogfacility is set either to 'user' (when building initramfs) or
# 'daemon' (when booting).
#
# Logging level set by the variable means that messages from this logging level
# and above (FATAL is the highest) will be shown. Logging levels may be set
# independently for each destination (stderr, syslog, file, kmsg).
#
# @see dlog_init()


## @brief Initializes dracut Logger.
#
# @retval 1 if something has gone wrong
# @retval 0 on success.
#
# @note This function need to be called before any other from this file.
#
# If any of the variables is not set, this function set it to default:
#   - @var stdloglvl = 4 (info)
#   - @var sysloglvl = 0 (no logging)
#   - @var fileloglvl is set to 4 when @var logfile is set too, otherwise it's
#   - @var kmsgloglvl = 0 (no logging)
#   set to 0
#
# @warning Function sets global variables @var maxloglvl and @syslogfacility.
# See file doc comment for details.
dlog_init() {
    local __oldumask
    local ret=0; local errmsg
    [ -z &quot;$stdloglvl&quot; ] &amp;&amp; stdloglvl=4
    [ -z &quot;$sysloglvl&quot; ] &amp;&amp; sysloglvl=0
    [ -z &quot;$kmsgloglvl&quot; ] &amp;&amp; kmsgloglvl=0
    # Skip initialization if it's already done.
    [ -n &quot;$maxloglvl&quot; ] &amp;&amp; return 0

    if [ -z &quot;$fileloglvl&quot; ]; then
        [ -w &quot;$logfile&quot; ] &amp;&amp; fileloglvl=4 || fileloglvl=0
    elif (( $fileloglvl &gt; 0 )); then
        if [[ $logfile ]]; then
            __oldumask=$(umask)
            umask 0377
            ! [ -e &quot;$logfile&quot; ] &amp;&amp; &gt;&quot;$logfile&quot;
            umask $__oldumask
            if [ -w &quot;$logfile&quot; -a -f &quot;$logfile&quot; ]; then
            # Mark new run in the log file
                echo &gt;&gt;&quot;$logfile&quot;
                if command -v date &gt;/dev/null; then
                    echo &quot;=== $(date) ===&quot; &gt;&gt;&quot;$logfile&quot;
                else
                    echo &quot;===============================================&quot; &gt;&gt;&quot;$logfile&quot;
                fi
                echo &gt;&gt;&quot;$logfile&quot;
            else
            # We cannot log to file, so turn this facility off.
                fileloglvl=0
                ret=1
                errmsg=&quot;'$logfile' is not a writable file&quot;
            fi
        fi
    fi

    if (( $UID  != 0 )); then
        kmsgloglvl=0
        sysloglvl=0
    fi

    if (( $sysloglvl &gt; 0 )); then
        if [[ -d /run/systemd/journal ]] \
            &amp;&amp; type -P systemd-cat &amp;&gt;/dev/null \
            &amp;&amp; systemctl --quiet is-active systemd-journald.socket &amp;&gt;/dev/null \
            &amp;&amp; { echo &quot;dracut-$DRACUT_VERSION&quot; | systemd-cat -t 'dracut' &amp;&gt;/dev/null; } ; then
            readonly _systemdcatfile=&quot;$DRACUT_TMPDIR/systemd-cat&quot;
            mkfifo &quot;$_systemdcatfile&quot;
            readonly _dlogfd=15
            systemd-cat -t 'dracut' --level-prefix=true &lt;&quot;$_systemdcatfile&quot; &amp;
            exec 15&gt;&quot;$_systemdcatfile&quot;
        elif ! [ -S /dev/log -a -w /dev/log ] || ! command -v logger &gt;/dev/null; then
            # We cannot log to syslog, so turn this facility off.
            kmsgloglvl=$sysloglvl
            sysloglvl=0
            ret=1
            errmsg=&quot;No '/dev/log' or 'logger' included for syslog logging&quot;
        fi
    fi

    if (($sysloglvl &gt; 0)) || (($kmsgloglvl &gt; 0 )); then
        if [ -n &quot;$dracutbasedir&quot; ]; then
            readonly syslogfacility=user
        else
            readonly syslogfacility=daemon
        fi
        export syslogfacility
    fi

    local lvl; local maxloglvl_l=0
    for lvl in $stdloglvl $sysloglvl $fileloglvl $kmsgloglvl; do
        (( $lvl &gt; $maxloglvl_l )) &amp;&amp; maxloglvl_l=$lvl
    done
    readonly maxloglvl=$maxloglvl_l
    export maxloglvl


    if (($stdloglvl &lt; 6)) &amp;&amp; (($kmsgloglvl &lt; 6)) &amp;&amp; (($fileloglvl &lt; 6)) &amp;&amp; (($sysloglvl &lt; 6)); then
        unset dtrace
        dtrace() { :; };
    fi

    if (($stdloglvl &lt; 5)) &amp;&amp; (($kmsgloglvl &lt; 5)) &amp;&amp; (($fileloglvl &lt; 5)) &amp;&amp; (($sysloglvl &lt; 5)); then
        unset ddebug
        ddebug() { :; };
    fi

    if (($stdloglvl &lt; 4)) &amp;&amp; (($kmsgloglvl &lt; 4)) &amp;&amp; (($fileloglvl &lt; 4)) &amp;&amp; (($sysloglvl &lt; 4)); then
        unset dinfo
        dinfo() { :; };
    fi

    if (($stdloglvl &lt; 3)) &amp;&amp; (($kmsgloglvl &lt; 3)) &amp;&amp; (($fileloglvl &lt; 3)) &amp;&amp; (($sysloglvl &lt; 3)); then
        unset dwarn
        dwarn() { :; };
        unset dwarning
        dwarning() { :; };
    fi

    if (($stdloglvl &lt; 2)) &amp;&amp; (($kmsgloglvl &lt; 2)) &amp;&amp; (($fileloglvl &lt; 2)) &amp;&amp; (($sysloglvl &lt; 2)); then
        unset derror
        derror() { :; };
    fi

    if (($stdloglvl &lt; 1)) &amp;&amp; (($kmsgloglvl &lt; 1)) &amp;&amp; (($fileloglvl &lt; 1)) &amp;&amp; (($sysloglvl &lt; 1)); then
        unset dfatal
        dfatal() { :; };
    fi

    [ -n &quot;$errmsg&quot; ] &amp;&amp; derror &quot;$errmsg&quot;

    return $ret
}

## @brief Converts numeric logging level to the first letter of level name.
#
# @param lvl Numeric logging level in range from 1 to 6.
# @retval 1 if @a lvl is out of range.
# @retval 0 if @a lvl is correct.
# @result Echoes first letter of level name.
_lvl2char() {
    case &quot;$1&quot; in
        1) echo F;;
        2) echo E;;
        3) echo W;;
        4) echo I;;
        5) echo D;;
        6) echo T;;
        *) return 1;;
    esac
}

## @brief Converts numeric level to logger priority defined by POSIX.2.
#
# @param lvl Numeric logging level in range from 1 to 6.
# @retval 1 if @a lvl is out of range.
# @retval 0 if @a lvl is correct.
# @result Echoes logger priority.
_lvl2syspri() {
    printf $syslogfacility.
    case &quot;$1&quot; in
        1) echo crit;;
        2) echo error;;
        3) echo warning;;
        4) echo info;;
        5) echo debug;;
        6) echo debug;;
        *) return 1;;
    esac
}

## @brief Converts dracut-logger numeric level to syslog log level
#
# @param lvl Numeric logging level in range from 1 to 6.
# @retval 1 if @a lvl is out of range.
# @retval 0 if @a lvl is correct.
# @result Echoes kernel console numeric log level
#
# Conversion is done as follows:
#
# &lt;tt&gt;
#   none     -&gt; LOG_EMERG (0)
#   none     -&gt; LOG_ALERT (1)
#   FATAL(1) -&gt; LOG_CRIT (2)
#   ERROR(2) -&gt; LOG_ERR (3)
#   WARN(3)  -&gt; LOG_WARNING (4)
#   none     -&gt; LOG_NOTICE (5)
#   INFO(4)  -&gt; LOG_INFO (6)
#   DEBUG(5) -&gt; LOG_DEBUG (7)
#   TRACE(6) /
# &lt;/tt&gt;
#
# @see /usr/include/sys/syslog.h
_dlvl2syslvl() {
    local lvl

    case &quot;$1&quot; in
        1) lvl=2;;
        2) lvl=3;;
        3) lvl=4;;
        4) lvl=6;;
        5) lvl=7;;
        6) lvl=7;;
        *) return 1;;
    esac

    [ &quot;$syslogfacility&quot; = user ] &amp;&amp; echo $((8+$lvl)) || echo $((24+$lvl))
}

## @brief Prints to stderr and/or writes to file, to syslog and/or /dev/kmsg
# given message with given level (priority).
#
# @param lvl Numeric logging level.
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
#
# @note This function is not supposed to be called manually. Please use
# dtrace(), ddebug(), or others instead which wrap this one.
#
# This is core logging function which logs given message to standard error, file
# and/or syslog (with POSIX shell command &lt;tt&gt;logger&lt;/tt&gt;) and/or to /dev/kmsg.
# The format is following:
#
# &lt;tt&gt;X: some message&lt;/tt&gt;
#
# where @c X is the first letter of logging level. See module description for
# details on that.
#
# Message to syslog is sent with tag @c dracut. Priorities are mapped as
# following:
#   - @c FATAL to @c crit
#   - @c ERROR to @c error
#   - @c WARN to @c warning
#   - @c INFO to @c info
#   - @c DEBUG and @c TRACE both to @c debug
_do_dlog() {
    local lvl=&quot;$1&quot;; shift
    local lvlc=$(_lvl2char &quot;$lvl&quot;) || return 0
    local msg=&quot;$*&quot;
    local lmsg=&quot;$lvlc: $*&quot;

    (( $lvl &lt;= $stdloglvl )) &amp;&amp; printf -- 'dracut: %s\n' &quot;$msg&quot; &gt;&amp;2

    if (( $lvl &lt;= $sysloglvl )); then
        if [[ &quot;$_dlogfd&quot; ]]; then
            printf -- &quot;&lt;%s&gt;%s\n&quot; &quot;$(($(_dlvl2syslvl $lvl) &amp; 7))&quot; &quot;$msg&quot; &gt;&amp;$_dlogfd
        else
            logger -t &quot;dracut[$$]&quot; -p $(_lvl2syspri $lvl) -- &quot;$msg&quot;
        fi
    fi

    if (( $lvl &lt;= $fileloglvl )) &amp;&amp; [[ -w &quot;$logfile&quot; ]] &amp;&amp; [[ -f &quot;$logfile&quot; ]]; then
        echo &quot;$lmsg&quot; &gt;&gt;&quot;$logfile&quot;
    fi

    (( $lvl &lt;= $kmsgloglvl )) &amp;&amp; \
        echo &quot;&lt;$(_dlvl2syslvl $lvl)&gt;dracut[$$] $msg&quot; &gt;/dev/kmsg
}

## @brief Internal helper function for _do_dlog()
#
# @param lvl Numeric logging level.
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
#
# @note This function is not supposed to be called manually. Please use
# dtrace(), ddebug(), or others instead which wrap this one.
#
# This function calls _do_dlog() either with parameter msg, or if
# none is given, it will read standard input and will use every line as
# a message.
#
# This enables:
# dwarn &quot;This is a warning&quot;
# echo &quot;This is a warning&quot; | dwarn
dlog() {
    [ -z &quot;$maxloglvl&quot; ] &amp;&amp; return 0
    (( $1 &lt;= $maxloglvl )) || return 0

    if (( $# &gt; 1 )); then
        _do_dlog &quot;$@&quot;
    else
        while read line || [ -n &quot;$line&quot; ]; do
            _do_dlog &quot;$1&quot; &quot;$line&quot;
        done
    fi
}

## @brief Logs message at TRACE level (6)
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
dtrace() {
    set +x
    dlog 6 &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}

## @brief Logs message at DEBUG level (5)
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
ddebug() {
    set +x
    dlog 5 &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}

## @brief Logs message at INFO level (4)
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
dinfo() {
    set +x
    dlog 4 &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}

## @brief Logs message at WARN level (3)
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
dwarn() {
    set +x
    dlog 3 &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}

## @brief It's an alias to dwarn() function.
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
dwarning() {
    set +x
    dwarn &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}

## @brief Logs message at ERROR level (2)
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
derror() {
    set +x
    dlog 2 &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}

## @brief Logs message at FATAL level (1)
#
# @param msg Message.
# @retval 0 It's always returned, even if logging failed.
dfatal() {
    set +x
    dlog 1 &quot;$@&quot;
    [ -n &quot;$debug&quot; ] &amp;&amp; set -x || :
}
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