[PATCH] Completion: Add _log_priorities, _logger

[dana <dana@xxxxxxx>]

This patch does the following:

* Adds a new type function called _log_priorities, which completes
  syslog-style facilities and severity levels

* Updates the four functions i found that already take syslog priorities to
  use _log_priorities

* Adds a new function for the logger utility (which also uses _log_priorities
  obv)

I tried to make _log_priorities featureful enough to suit all of the obvious
use cases i could think of; let me know if it seems weird though. (The strange
option letters were, as with _bind_addresses, chosen to avoid conflicting with
compadd. Daniel once suggested that we come up with some standard calling
convention that resolves this head ache, but i haven't personally given it
much further thought)

This is also another case where i needed a host-with-port utility function
that properly handles IPv6 bracket syntax. I mentioned that i was working on
that a while ago, but i had trouble coming up with a good generalised API.
Might revisit some day

dana


diff --git a/Completion/Unix/Type/_log_priorities b/Completion/Unix/Type/_log_priorities
new file mode 100644
index 000000000..42cf485dc
--- /dev/null
+++ b/Completion/Unix/Type/_log_priorities
@@ -0,0 +1,70 @@
+#autoload
+
+# Complete syslog-style priorities/facilities/levels
+#
+# Note: 'Priority' according to syslog(3) refers to a severity level optionally
+# ORed with a facility. We use it here in a somewhat similar manner, as this
+# seems to cover the most ground, though we also support completing facilities
+# alone.
+#
+# By default, a case-insensitive facility.level pair is completed.
+#
+# Some tools that accept symbolic facility/level names also accept numbers
+# corresponding to their associated values defined in syslog.h. Since these
+# numbers vary across systems, we don't attempt to complete them.
+#
+# Options:
+#   -y  Complete only facilities
+#   -Y  Complete only severity levels
+#   -z  Complete only lower-case names
+#   -Z  Complete only upper-case names
+
+local -a expl facilities levels ca_opts
+local -A opts
+
+# Facilities vary across systems too, but these seem common enough
+facilities=(
+  kern
+  user
+  mail
+  daemon
+  auth
+  syslog
+  lpr
+  news
+  uucp
+  cron
+  authpriv
+  ftp
+  ntp
+  security
+  local{0..7}
+)
+levels=(
+  emerg   # 'panic' is deprecated
+  alert
+  crit
+  err     # 'error' is deprecated
+  warning # 'warn' is deprecated
+  notice
+  info
+  debug
+)
+
+zparseopts -A opts -D -E -- y Y z Z
+
+if (( $+opts[-Z] )); then
+  facilities=( ${(@U)facilities} )
+  levels=( ${(@U)levels} )
+elif (( ! $+opts[-z] )); then
+  ca_opts+=( -M 'm:{a-zA-Z}={A-Za-z}' )
+fi
+
+if (( $+opts[-Y] )) || { (( ! $+opts[-y] )) && compset -P '[^.]##.' }; then
+  _wanted levels expl 'log severity level' \
+      compadd -a "$@" "${(@)ca_opts}" - levels
+else
+  (( ! $+opts[-y] )) && ! compset -S '.[^.]##' && ca_opts+=( -qS. )
+  _wanted facilities expl 'log facility' \
+      compadd -a "$@" "${(@)ca_opts}" - facilities
+fi

diff --git a/Completion/BSD/Command/_pfctl b/Completion/BSD/Command/_pfctl
index 23898882f..a2a81b5db 100644
--- a/Completion/BSD/Command/_pfctl
+++ b/Completion/BSD/Command/_pfctl
@@ -58,9 +58,7 @@ _pf_tables() {
 
 case $OSTYPE in
   openbsd*)
-    pfctl_debug_level=(
-      emerg alert crit err warning notice info debug
-    )
+    _log_priorities -Y -O pfctl_debug_level
     args=(
       '-L+[load pf states from specified state file]:file:_files'
       "-N[don't perform domain name resolution]"

diff --git a/Completion/Linux/Command/_iptables b/Completion/Linux/Command/_iptables
index 27c801da1..d4d678579 100644
--- a/Completion/Linux/Command/_iptables
+++ b/Completion/Linux/Command/_iptables
@@ -57,7 +57,7 @@ case ${prev[${prev[(I)-j|--jump]}+1]}; in
   ECN) args+=( '--ecn-tcp-remove[remove all ECN bits from TCP header]' ) ;;
   LOG)
     args+=(
-      '--log-level[specify level of logging]:log level:(debug info notice warning err crit alert emerg)'
+      '--log-level[specify level of logging]: :_log_priorities -Y'
       '--log-prefix[specify prefix string for log message]:string'
       '--log-tcp-sequence[log TCP sequence numbers]'
       '--log-tcp-options[log TCP options]'

diff --git a/Completion/Unix/Command/_rclone b/Completion/Unix/Command/_rclone
index 01d851fa1..698a94772 100644
--- a/Completion/Unix/Command/_rclone
+++ b/Completion/Unix/Command/_rclone
@@ -147,7 +147,7 @@ _arguments -C \
   '--streaming-upload-cutoff[specify size cutoff for switching to chunked upload]:size [100k]' \
   '--suffix[specify suffix for use with --backup-dir]:string' \
   '--syslog[use syslog for logging]' \
-  '--syslog-facility[facility for syslog, eg KERN,USER,...]:string [DAEMON]' \
+  '--syslog-facility[specify syslog facility]:log facility [DAEMON]:_log_priorities -yZ' \
   '--timeout[specify IO idle timeout]:duration [5m0s]' \
   '--tpslimit[limit HTTP transactions per second to this]:float' \
   '--tpslimit-burst[max burst of transactions for --tpslimit]:int [1]' \

diff --git a/Completion/Unix/Command/_ssh b/Completion/Unix/Command/_ssh
index 0775590e6..cc7ed563c 100644
--- a/Completion/Unix/Command/_ssh
+++ b/Completion/Unix/Command/_ssh
@@ -441,7 +441,7 @@ _ssh () {
           _wanted values expl 'value' compadd yes no ask accept-new off && ret=0
           ;;
         (#i)syslogfacility=*)
-          _wanted facilities expl 'facility' compadd -M 'm:{a-z}={A-Z}' DAEMON USER AUTH LOCAL{0,1,2,3,4,5,6,7} && ret=0
+          _log_priorities -y && ret=0
           ;;
         (#i)(verifyhostkeydns|updatehostkeys)=*)
           _wanted values expl 'truthish value' compadd yes no ask && ret=0

diff --git a/Completion/Unix/Command/_logger b/Completion/Unix/Command/_logger
new file mode 100644
index 000000000..180e35b89
--- /dev/null
+++ b/Completion/Unix/Command/_logger
@@ -0,0 +1,93 @@
+#compdef logger
+
+local variant
+local -a args aopts=( -A '-*' )
+
+_pick_variant -r variant util-linux=util-linux $OSTYPE --version
+
+case $variant in
+  *)
+    args+=(
+      '(-f -e --file --journald --prio-prefix --skip-empty)*: :_guard "^-*" message'
+      '(: * --journald)'{-f+,--file=}'[log contents of specified file]: :_files'
+      '(--id)-i[log with PID of logger process]'
+      '(-p --priority)'{-p+,--priority=}'[log with specified priority]: :_log_priorities'
+      '(-t --tag)'{-t+,--tag=}'[log with specified tag]:tag'
+    )
+    ;|
+  darwin*|dragonfly*|freebsd*|linux*|netbsd*|openbsd*)
+    args+=(
+      '(-s --stderr)'{-s,--stderr}'[also log to stderr (LOG_PERROR)]'
+    )
+    ;|
+  netbsd*|openbsd*)
+    args+=(
+      '-c[log to console if unable to log normally (LOG_CONS)]'
+    )
+    ;|
+  dragonfly*|freebsd*)
+    args+=(
+      '(-6)-4[log via IPv4 only]'
+      '(-4)-6[log via IPv6 only]'
+      '-A[log to all IP addresses associated with remote host name]'
+      # @todo Complete UNIX-domain sockets
+      '-h+[log to specified remote host or UNIX-domain socket]:remote syslog host:_hosts'
+    )
+    ;|
+  freebsd*)
+    args+=(
+      '-H+[specify host name for message header]: :_hosts'
+      '-P+[log to specified port (with -h)]:remote syslog port:_ports'
+      # @todo This is another case where we need a dedicated _hosts_ports
+      # function which can properly handle bracketed IPv6 address syntax
+      '-S+[specify source address/port (with -h)]: :_bind_addresses -0bh'
+    )
+    ;;
+  netbsd*)
+    args+=(
+      '-d+[log specified structured data]:structured data'
+      '-m+[specify RFC5424 MSGID]:MSGID'
+      '-n[open log connection immediately (LOG_NDELAY)]'
+    )
+    ;;
+  util-linux)
+    aopts=( )
+    args+=(
+      '(-d -T --tcp --udp)'{-d,--udp}'[log via UDP only (with -n)]'
+      '(: * -e --skip-empty)'{-e,--skip-empty}'[ignore empty lines in input (with -f or stdin)]'
+      '(-i)--id=-[log with PID of logger process or specified PID]:: :_pids'
+      '(--rfc3164)--msgid=[specify RFC5424 MSGID]:MSGID'
+      '(-n --server)'{-n+,--server=}'[log to specified remote host]:remote syslog host:_hosts'
+      '--no-act[do not actually log]'
+      '--octet-count[use RFC6587 octet counting]'
+      '(-P --port)'{-P+,--port=}'[log to specified port (with -n)]:remote syslog port:_ports'
+      '(: *)--prio-prefix[look for priority prefix <n> on each line (with -f or stdin)]'
+      '(--msgid --rfc5424 --sd-id --sd-param)--rfc3164[use RFC3164 BSD syslog protocol]'
+      '(--rfc3164)--rfc5424=-[use RFC5424 syslog protocol with optional exceptions]:protocol exceptions:((
+        nohost\:"suppress gethostname(2) information"
+        notime\:"suppress complete sender time stamp (implies notq)"
+        notq\:"suppress time-quality structured data"
+      ))'
+      # @todo We could do a better job of completing these next two. The
+      # util-linux man page describes the format and some of the known values.
+      # Also, this is one of those cases where the options have to be given in
+      # order, i.e., each --sd-param must be preceded by --sd-id and vice versa
+      '(--rfc3164)*--sd-id=[specify RFC5424 structured-data element ID]:structured-data element ID'
+      '(--rfc3164)*--sd-param=[specify RFC5424 structured-data element parameter]:structured-data element parameter (name=value)'
+      '--size=[specify maximum message size]:message size (bytes)'
+      '--socket-errors=-[specify socket error-printing behavior]:mode::(auto off on)'
+      '(-u --socket)'{-u+,--socket=}'[write to specified socket instead of default]:syslog socket:_files -g "*(-=D)"'
+      '(-d -T --tcp --udp)'{-t,--tcp}'[log via TCP only (with -n)]'
+      '(: * -)'{-V,--version}'[display version information]'
+      '(: * -)'{-h,--help}'[display help information]'
+    )
+    # This option actually ignores many other options, like -p
+    (( $+commands[journalctl] )) && args+=(
+      '(: * -f --file)--journald=-[log systemd journal entry from stdin or specified file]: ::_files'
+    )
+    ;;
+esac
+
+[[ $variant == util-linux ]] || args=( ${args:#(\([^\)]#\)|)(\*|)--*} )
+
+_arguments -s -S $aopts : $args