mirror of
https://github.com/DictXiong/dotfiles.git
synced 2024-11-24 16:37:00 +08:00
Merge 3d4a264a30
into 483f7fd7f3
This commit is contained in:
commit
b2bed1a2b5
|
@ -9,6 +9,8 @@
|
||||||
quotepath = false # chinese chars
|
quotepath = false # chinese chars
|
||||||
[push]
|
[push]
|
||||||
autoSetupRemote = true
|
autoSetupRemote = true
|
||||||
|
[pull]
|
||||||
|
ff = only
|
||||||
[branch]
|
[branch]
|
||||||
# Show most recently changed branches first.
|
# Show most recently changed branches first.
|
||||||
sort = -committerdate
|
sort = -committerdate
|
||||||
|
|
6
.zshrc2
6
.zshrc2
|
@ -102,6 +102,9 @@ fi
|
||||||
alias "pls"='sudo $(fc -ln -1)'
|
alias "pls"='sudo $(fc -ln -1)'
|
||||||
alias "se"='sudo -sE'
|
alias "se"='sudo -sE'
|
||||||
alias "sl"='sudo zsh -l'
|
alias "sl"='sudo zsh -l'
|
||||||
|
alias "cps"='rsync -avh --info=progress2'
|
||||||
|
alias "mvs"='rsync -avh --info=progress2 --remove-source-files'
|
||||||
|
if [[ $("$DOTFILES/tools/common.sh" get_os_type) == "linux" ]]; then alias "ping"='ping -n'; fi
|
||||||
alias "pbd"='ping baidu.com'
|
alias "pbd"='ping baidu.com'
|
||||||
alias "p114"='ping 114.114.114.114'
|
alias "p114"='ping 114.114.114.114'
|
||||||
alias "p666"='ping6 2001:da8::666'
|
alias "p666"='ping6 2001:da8::666'
|
||||||
|
@ -110,9 +113,6 @@ alias "cbds"='curl https://www.baidu.com'
|
||||||
alias "gdebug"='git add -A; git commit --allow-empty -m "bug fix ($(date))"'
|
alias "gdebug"='git add -A; git commit --allow-empty -m "bug fix ($(date))"'
|
||||||
alias "ls"='ls --color=tty'
|
alias "ls"='ls --color=tty'
|
||||||
alias "l"='ls -lAGh --time-style="+%y-%m-%d %H:%M"'
|
alias "l"='ls -lAGh --time-style="+%y-%m-%d %H:%M"'
|
||||||
if [[ -x $(command -v trash) ]]; then
|
|
||||||
alias "rm"="echo use the full path i.e. '/bin/rm'\; consider using trash"
|
|
||||||
fi
|
|
||||||
gbes() { git for-each-ref --sort=-committerdate refs/heads refs/remotes --format="%(authordate:format:%y-%m-%d.%a %H:%M %z)|%(color:red)%(objectname:short)|%(color:yellow)%(refname:short)%(color:reset)|%(color:reset)%(authorname): %(color:green)%(subject)" --color=always | column -ts"|" | less -FX }
|
gbes() { git for-each-ref --sort=-committerdate refs/heads refs/remotes --format="%(authordate:format:%y-%m-%d.%a %H:%M %z)|%(color:red)%(objectname:short)|%(color:yellow)%(refname:short)%(color:reset)|%(color:reset)%(authorname): %(color:green)%(subject)" --color=always | column -ts"|" | less -FX }
|
||||||
sagt() { eval "$($DOTFILES/tools/sagent.sh $@)" }
|
sagt() { eval "$($DOTFILES/tools/sagent.sh $@)" }
|
||||||
|
|
||||||
|
|
|
@ -330,7 +330,7 @@ for i in ${GOT_OPTS[@]}; do
|
||||||
-a|--auto ) INSTALL_DEP=1 ;;
|
-a|--auto ) INSTALL_DEP=1 ;;
|
||||||
-H|--hist|--history ) store_hist=1 ;;
|
-H|--hist|--history ) store_hist=1 ;;
|
||||||
-x ) store_config=1 ;;
|
-x ) store_config=1 ;;
|
||||||
--no-ssh ) unset HOME_SYMLINKS_SRC[0]; unset HOME_SYMLINKS_DST[0] ;;
|
--no-auth-info ) HOME_SYMLINKS_SRC=(); HOME_SYMLINKS_DST=() ;;
|
||||||
* ) fmt_fatal "unknown option \"$i\"" ;;
|
* ) fmt_fatal "unknown option \"$i\"" ;;
|
||||||
esac
|
esac
|
||||||
done
|
done
|
||||||
|
|
56
riot-config.sh
Normal file
56
riot-config.sh
Normal file
|
@ -0,0 +1,56 @@
|
||||||
|
#!/bin/false
|
||||||
|
|
||||||
|
# remotes
|
||||||
|
j.remote() {
|
||||||
|
remote=ssh.beardic.cn
|
||||||
|
RET_PORT=${RET_PORT:-24022}
|
||||||
|
RET_USERNAME=${RET_USERNAME:-root}
|
||||||
|
RET_TRUST_SERVER=1
|
||||||
|
}
|
||||||
|
|
||||||
|
nasp.remote() {
|
||||||
|
remote=nasp.ob.ac.cn
|
||||||
|
RET_PORT=${RET_PORT:-36022}
|
||||||
|
RET_USERNAME=${RET_USERNAME:-ssh}
|
||||||
|
RET_TRUST_SERVER=1
|
||||||
|
}
|
||||||
|
|
||||||
|
# domains
|
||||||
|
.domain() {
|
||||||
|
RET_USERNAME=${RET_USERNAME:-root}
|
||||||
|
}
|
||||||
|
|
||||||
|
i.domain() {
|
||||||
|
RET_HOSTNAME=$host.ibd.ink
|
||||||
|
RET_PORT=${RET_PORT:-12022}
|
||||||
|
RET_USERNAME=${RET_USERNAME:-root}
|
||||||
|
RET_TRUST_SERVER=1
|
||||||
|
}
|
||||||
|
|
||||||
|
42.domain() {
|
||||||
|
RET_HOSTNAME=$host.i.bd.dn42
|
||||||
|
RET_PORT=${RET_PORT:-12022}
|
||||||
|
RET_USERNAME=${RET_USERNAME:-root}
|
||||||
|
RET_TRUST_SERVER=1
|
||||||
|
}
|
||||||
|
|
||||||
|
x.domain() {
|
||||||
|
RET_HOSTNAME=ssh.beardic.cn
|
||||||
|
local tmp=$(sha256sum <<< "$host" | tr -cd "[:digit:]")
|
||||||
|
tmp=${tmp:0:4}
|
||||||
|
RET_PORT=$((10#$tmp+36000))
|
||||||
|
RET_USERNAME=root
|
||||||
|
RET_TRUST_SERVER=1
|
||||||
|
}
|
||||||
|
|
||||||
|
nasp.domain() {
|
||||||
|
RET_HOSTNAME=$host
|
||||||
|
RET_PORT=${RET_PORT:-12022}
|
||||||
|
RET_USERNAME=${RET_USERNAME:-dictxiong}
|
||||||
|
RET_JUMP_SERVER="ssh@nasp.ob.ac.cn:36022"
|
||||||
|
RET_TRUST_SERVER=1
|
||||||
|
}
|
||||||
|
|
||||||
|
default.domain() {
|
||||||
|
i.domain
|
||||||
|
}
|
|
@ -21,5 +21,5 @@ if [[ -z "$IMAGE" ]]; then
|
||||||
fmt_fatal "image not found"
|
fmt_fatal "image not found"
|
||||||
else
|
else
|
||||||
fmt_note "--> ${IMAGE_META[@]}"
|
fmt_note "--> ${IMAGE_META[@]}"
|
||||||
$SUDO docker run ${2:+"--name"} $2 -itd $IMAGE sh
|
$SUDO docker run ${2:+"--name"} $2 -itd --restart=unless-stopped $IMAGE sh
|
||||||
fi
|
fi
|
||||||
|
|
97
scripts/riot
97
scripts/riot
|
@ -4,6 +4,19 @@ THIS_DIR=$( cd "$( dirname "${BASH_SOURCE[0]:-${(%):-%x}}" )" && pwd )
|
||||||
source "$THIS_DIR/../tools/common.sh"
|
source "$THIS_DIR/../tools/common.sh"
|
||||||
RIOT_TRUST_CLIENT=${RIOT_TRUST_CLIENT:-${DFS_TRUST:-0}}
|
RIOT_TRUST_CLIENT=${RIOT_TRUST_CLIENT:-${DFS_TRUST:-0}}
|
||||||
RIOT_TRUST_SERVER=${RIOT_TRUST_SERVER:-0}
|
RIOT_TRUST_SERVER=${RIOT_TRUST_SERVER:-0}
|
||||||
|
RIOT_EXTRA_OPTIONS=""
|
||||||
|
|
||||||
|
# config
|
||||||
|
RIOT_CONFIG_FILES=(
|
||||||
|
"$DOTFILES/riot-config.sh"
|
||||||
|
"$HOME/.config/riot-config.sh"
|
||||||
|
"riot-config.sh"
|
||||||
|
)
|
||||||
|
for file in "${RIOT_CONFIG_FILES[@]}"; do
|
||||||
|
if [[ -f "$file" ]]; then
|
||||||
|
source "$file"
|
||||||
|
fi
|
||||||
|
done
|
||||||
|
|
||||||
# check if port number valid
|
# check if port number valid
|
||||||
check_port() {
|
check_port() {
|
||||||
|
@ -29,14 +42,6 @@ get_server_meta() {
|
||||||
RET_JUMP_SERVER="" # optional
|
RET_JUMP_SERVER="" # optional
|
||||||
# body
|
# body
|
||||||
local remote="$1"
|
local remote="$1"
|
||||||
# shortcuts
|
|
||||||
if [[ "$remote" == "i" ]]; then
|
|
||||||
remote="sir0.ibd"
|
|
||||||
elif [[ "$remote" == "x" ]]; then
|
|
||||||
remote="bj1.ibd"
|
|
||||||
elif [[ "$remote" == "j" ]]; then
|
|
||||||
remote="sir0.ibd:36122"
|
|
||||||
fi
|
|
||||||
# if in the form user@...
|
# if in the form user@...
|
||||||
if [[ "$remote" == *@* ]]; then
|
if [[ "$remote" == *@* ]]; then
|
||||||
RET_USERNAME=${remote%%@*}
|
RET_USERNAME=${remote%%@*}
|
||||||
|
@ -49,46 +54,25 @@ get_server_meta() {
|
||||||
remote=${remote%:*}
|
remote=${remote%:*}
|
||||||
check_port $RET_PORT || fmt_fatal invalid port number \"$RET_PORT\"
|
check_port $RET_PORT || fmt_fatal invalid port number \"$RET_PORT\"
|
||||||
fi
|
fi
|
||||||
|
# presets -- match remote
|
||||||
|
local remote_func="$remote.remote"
|
||||||
|
if is_function "$remote_func"; then
|
||||||
|
"$remote_func"
|
||||||
|
fi
|
||||||
# presets -- match domain
|
# presets -- match domain
|
||||||
|
RET_HOSTNAME=${remote}
|
||||||
local domain=${remote##*.}
|
local domain=${remote##*.}
|
||||||
local host=${remote%.*}
|
local host=${remote%.*}
|
||||||
# if there's no dot
|
# if there's no dot
|
||||||
if [[ "$host" == "$domain" && "$host" != "["*"]" ]]; then
|
if [[ "$host" == "$domain" && "$host" != "["*"]" ]]; then
|
||||||
domain="ibd"
|
domain="default"
|
||||||
|
fi
|
||||||
|
local domain_func="$domain.domain"
|
||||||
|
if is_function "$domain_func"; then
|
||||||
|
"$domain_func"
|
||||||
|
elif is_function ".domain"; then
|
||||||
|
".domain"
|
||||||
fi
|
fi
|
||||||
case $domain in
|
|
||||||
i|ibd )
|
|
||||||
RET_HOSTNAME=$host.ibd.ink
|
|
||||||
RET_PORT=${RET_PORT:-12022}
|
|
||||||
RET_USERNAME=${RET_USERNAME:-root}
|
|
||||||
RET_TRUST_SERVER=1
|
|
||||||
;;
|
|
||||||
nasp )
|
|
||||||
RET_HOSTNAME=$host
|
|
||||||
RET_PORT=${RET_PORT:-12022}
|
|
||||||
RET_USERNAME=${RET_USERNAME:-dictxiong}
|
|
||||||
RET_JUMP_SERVER="ssh@nasp.ob.ac.cn:36022"
|
|
||||||
RET_TRUST_SERVER=1
|
|
||||||
;;
|
|
||||||
x|proxied )
|
|
||||||
RET_HOSTNAME=proxy.beardic.cn
|
|
||||||
local tmp=$(sha256sum <<< "$host" | tr -cd "[:digit:]")
|
|
||||||
tmp=${tmp:0:4}
|
|
||||||
RET_PORT=$((10#$tmp+36000))
|
|
||||||
RET_USERNAME=root
|
|
||||||
RET_TRUST_SERVER=1
|
|
||||||
;;
|
|
||||||
box[0-9] )
|
|
||||||
RET_HOSTNAME=$host
|
|
||||||
RET_PORT=${RET_PORT:-12022}
|
|
||||||
RET_USERNAME=${RET_USERNAME:-root}
|
|
||||||
RET_JUMP_SERVER="root@$domain.ibd.ink:12022"
|
|
||||||
RET_TRUST_SERVER=1
|
|
||||||
;;
|
|
||||||
* )
|
|
||||||
test -z "$domain" || fmt_warning "unknown domain: \"$domain\". will try as host name"
|
|
||||||
RET_HOSTNAME="$remote"
|
|
||||||
esac
|
|
||||||
}
|
}
|
||||||
|
|
||||||
parse_remote() {
|
parse_remote() {
|
||||||
|
@ -150,7 +134,7 @@ prepare_ssh_cmd() {
|
||||||
else
|
else
|
||||||
local port_param='-p'
|
local port_param='-p'
|
||||||
fi
|
fi
|
||||||
echo "$ssh_bin ${PORT:+$port_param} $PORT $SSH_OPTIONS $SCP_SRC $USERNAME${USERNAME:+@}$SERVER $SCP_DST ${@:2}"
|
echo "$ssh_bin ${PORT:+$port_param} $PORT $SSH_OPTIONS $RIOT_EXTRA_OPTIONS $SCP_SRC $USERNAME${USERNAME:+@}$SERVER $SCP_DST ${@:2}"
|
||||||
}
|
}
|
||||||
|
|
||||||
# ssh
|
# ssh
|
||||||
|
@ -178,6 +162,18 @@ run_sshl()
|
||||||
eval_or_echo $cmd
|
eval_or_echo $cmd
|
||||||
}
|
}
|
||||||
|
|
||||||
|
# sshd
|
||||||
|
run_sshd()
|
||||||
|
{
|
||||||
|
local port=$(get_free_port)
|
||||||
|
|
||||||
|
SSH_OPTIONS="$SSH_OPTIONS -NC -D $port"
|
||||||
|
local cmd="$(prepare_ssh_cmd ssh)"
|
||||||
|
fmt_note "-->" $cmd
|
||||||
|
fmt_note " > please access localhost:$port"
|
||||||
|
eval_or_echo $cmd
|
||||||
|
}
|
||||||
|
|
||||||
# scp
|
# scp
|
||||||
run_scp() {
|
run_scp() {
|
||||||
local src="$1"
|
local src="$1"
|
||||||
|
@ -214,6 +210,15 @@ router() {
|
||||||
exit
|
exit
|
||||||
fi
|
fi
|
||||||
|
|
||||||
|
while [[ "$1" == -* ]]; do
|
||||||
|
RIOT_EXTRA_OPTIONS="$RIOT_EXTRA_OPTIONS $1"
|
||||||
|
if [[ "$1" == "-o" ]]; then
|
||||||
|
RIOT_EXTRA_OPTIONS="$RIOT_EXTRA_OPTIONS $2"
|
||||||
|
shift
|
||||||
|
fi
|
||||||
|
shift
|
||||||
|
done
|
||||||
|
|
||||||
IFS=',' read -ra remotes <<< "$1"
|
IFS=',' read -ra remotes <<< "$1"
|
||||||
for remote in "${remotes[@]}"; do
|
for remote in "${remotes[@]}"; do
|
||||||
if [[ -z "$remote" ]]; then
|
if [[ -z "$remote" ]]; then
|
||||||
|
@ -224,6 +229,9 @@ router() {
|
||||||
ssh|"" )
|
ssh|"" )
|
||||||
run_ssh ssh "${@:3}"
|
run_ssh ssh "${@:3}"
|
||||||
;;
|
;;
|
||||||
|
ping|ping6 )
|
||||||
|
run_ssh ssh "${@:2}"
|
||||||
|
;;
|
||||||
zssh )
|
zssh )
|
||||||
run_ssh zssh
|
run_ssh zssh
|
||||||
;;
|
;;
|
||||||
|
@ -234,6 +242,9 @@ router() {
|
||||||
test -n "$3" || fmt_fatal "no target address provided"
|
test -n "$3" || fmt_fatal "no target address provided"
|
||||||
run_sshl "$3"
|
run_sshl "$3"
|
||||||
;;
|
;;
|
||||||
|
sshd )
|
||||||
|
run_sshd
|
||||||
|
;;
|
||||||
scp )
|
scp )
|
||||||
test -n "$3" || fmt_fatal "no source path specified"
|
test -n "$3" || fmt_fatal "no source path specified"
|
||||||
test -n "$4" || fmt_fatal "no destination path specified"
|
test -n "$4" || fmt_fatal "no destination path specified"
|
||||||
|
|
|
@ -258,6 +258,10 @@ get_free_port() {
|
||||||
echo $port
|
echo $port
|
||||||
}
|
}
|
||||||
|
|
||||||
|
is_function() {
|
||||||
|
test "$(type -t "$1")" = "function"
|
||||||
|
}
|
||||||
|
|
||||||
# if bash-ed, else source-d
|
# if bash-ed, else source-d
|
||||||
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
|
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
|
||||||
$1 "${@:2}"
|
$1 "${@:2}"
|
||||||
|
|
|
@ -103,6 +103,7 @@ update_dns()
|
||||||
ip4=""
|
ip4=""
|
||||||
elif [[ "$DFS_DDNS_IP4" == "auto" ]]; then
|
elif [[ "$DFS_DDNS_IP4" == "auto" ]]; then
|
||||||
ip4="auto"
|
ip4="auto"
|
||||||
|
api_url="https://api4.beardic.cn"
|
||||||
elif [[ "$DFS_DDNS_IP4" == "api" ]]; then
|
elif [[ "$DFS_DDNS_IP4" == "api" ]]; then
|
||||||
ip4=$(curl $DFS_CURL_OPTIONS -sSL "https://api.ipify.org")
|
ip4=$(curl $DFS_CURL_OPTIONS -sSL "https://api.ipify.org")
|
||||||
elif [[ "$DFS_DDNS_IP4" == "http"* ]]; then
|
elif [[ "$DFS_DDNS_IP4" == "http"* ]]; then
|
||||||
|
|
|
@ -25,7 +25,7 @@ find_so_file()
|
||||||
create_agent()
|
create_agent()
|
||||||
{
|
{
|
||||||
local IFS=","
|
local IFS=","
|
||||||
ssh-agent -P "${SO_PATHS[*]}"
|
ssh-agent -P "${SO_PATHS[*]},/nix/store/*"
|
||||||
}
|
}
|
||||||
|
|
||||||
kill_agent()
|
kill_agent()
|
||||||
|
|
|
@ -38,7 +38,7 @@ test $(echo n | tools/common.sh ask_for_yN "test") = "0"
|
||||||
test $(echo | tools/common.sh ask_for_yN "test") = "0"
|
test $(echo | tools/common.sh ask_for_yN "test") = "0"
|
||||||
test $(echo | tools/common.sh ask_for_Yn "test") = "1"
|
test $(echo | tools/common.sh ask_for_Yn "test") = "1"
|
||||||
test $(DFS_QUIET=1 tools/common.sh ask_for_Yn "test") = "1"
|
test $(DFS_QUIET=1 tools/common.sh ask_for_Yn "test") = "1"
|
||||||
test "$(DFS_TRUST=1 riot time@is.impt:2222/yes@you-r.right/you@are.really.recht./ibd./try@it,another@host scp /tmp/ ./tmp -D 2>/dev/null)" = 'scp -P 12022 -o ControlMaster=auto -o ControlPath=/tmp/sshcm-%C -o PermitLocalCommand=yes -o ProxyJump=time@is.impt:2222,yes@you-r.right,you@are.really.recht.,ibd. -r try@it.ibd.ink:"/tmp/" "./tmp"
|
test "$(DFS_TRUST=1 riot time@is.impt:2222/yes@you-r.right/you@are.really.recht./ibd./try@it,another@host scp /tmp/ ./tmp -D 2>/dev/null)" = 'scp -P 12022 -o ControlMaster=auto -o ControlPath=/tmp/sshcm-%C -o PermitLocalCommand=yes -o ProxyJump=time@is.impt:2222,yes@you-r.right,you@are.really.recht.,root@ibd. -r try@it.ibd.ink:"/tmp/" "./tmp"
|
||||||
scp -P 12022 -o ControlMaster=auto -o ControlPath=/tmp/sshcm-%C -o PermitLocalCommand=yes -o ForwardX11=yes -o ForwardAgent=yes -r another@host.ibd.ink:"/tmp/" "./tmp"'
|
scp -P 12022 -o ControlMaster=auto -o ControlPath=/tmp/sshcm-%C -o PermitLocalCommand=yes -o ForwardX11=yes -o ForwardAgent=yes -r another@host.ibd.ink:"/tmp/" "./tmp"'
|
||||||
|
|
||||||
# check alias
|
# check alias
|
||||||
|
|
|
@ -10,8 +10,9 @@ INSTALL_COMMANDS=(\
|
||||||
[v2fly]="bash <(curl -L https://raw.githubusercontent.com/v2fly/fhs-install-v2ray/master/install-release.sh) #--remove" \
|
[v2fly]="bash <(curl -L https://raw.githubusercontent.com/v2fly/fhs-install-v2ray/master/install-release.sh) #--remove" \
|
||||||
[zerotier-one]='curl -s https://install.zerotier.com | sudo bash' \
|
[zerotier-one]='curl -s https://install.zerotier.com | sudo bash' \
|
||||||
[docker-ce]='curl -fsSL https://get.docker.com | sudo bash -s - --mirror Aliyun #--dry-run' \
|
[docker-ce]='curl -fsSL https://get.docker.com | sudo bash -s - --mirror Aliyun #--dry-run' \
|
||||||
[lemonbench]='curl -fsSL https://ilemonra.in/LemonBenchIntl | bash -s fast # or full' \
|
[lemonbench]='curl -fsSL https://raw.githubusercontent.com/LemonBench/LemonBench/main/LemonBench.sh | bash -s fast # or full' \
|
||||||
[nix]='sh <(curl -L https://nixos.org/nix/install) #--daemon' \
|
[nix]='sh <(curl -L https://nixos.org/nix/install) #--daemon' \
|
||||||
|
[alist]='curl -fsSL "https://alist.nn.ci/v3.sh" | bash -s install' \
|
||||||
)
|
)
|
||||||
|
|
||||||
install()
|
install()
|
||||||
|
|
|
@ -14,11 +14,11 @@ apt_install()
|
||||||
{
|
{
|
||||||
apt-get update -y
|
apt-get update -y
|
||||||
# lite
|
# lite
|
||||||
apt-get install -y git zsh bash tmux vim curl inetutils-ping less bsdmainutils
|
DEBIAN_FRONTEND=noninteractive apt-get install -y git zsh bash tmux vim curl iputils-ping less bsdmainutils
|
||||||
# full
|
# full
|
||||||
if [[ -z "$DFS_LITE" || "$DFS_LITE" == "0" ]]; then
|
if [[ -z "$DFS_LITE" || "$DFS_LITE" == "0" ]]; then
|
||||||
apt-get install -y wget dialog net-tools dnsutils netcat traceroute sudo python3 python3-pip cron openssh-client openssh-server htop gcc g++ cmake make zip
|
DEBIAN_FRONTEND=noninteractive apt-get install -y wget dialog net-tools dnsutils netcat traceroute sudo python3 python3-pip cron openssh-client openssh-server htop gcc g++ cmake make zip
|
||||||
for i in {fzf,ripgrep,man-db}; do apt-get install -y $i; done
|
for i in {fzf,ripgrep,man-db}; do DEBIAN_FRONTEND=noninteractive apt-get install -y $i; done
|
||||||
fi
|
fi
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue
Block a user