February 27, 20243 min read

Useful Bash Commands & Functions

A grab bag of .bashrc functions I re-add on every new machine: server shortcuts, SLURM/GPU job killers, and VPN login helpers.

#bash#linux#slurm

Alias

alias md=mkdir

bashrc settings

shopt -s autocd

Server shortcut function

server(){
    if [ $# -eq 0 ];then
        ssh -CX user@serverIP
    elif [ $1 = "port" ];then
        if [ -z "$4" ];then
            ssh -N -L $2:$3.serverIP:$2 user@serverIP
        else
            ssh -N -L $2:$3.serverIP:$4 user@serverIP
        fi
    elif [ $1 = "send" ];then
        rsync -rzvP $2 user@serverIP:$3
    elif [ $1 = "receive" ];then
        rsync -rzvP user@serverIP:$2 $3
    else
        ssh user@serverIP $1
    fi
}

Replace server with whatever name you like, user with your username, and serverIP with the server's address.

server — just logs you in.
server send yourLocation serverLocation — sends a file to the server.
server receive serverLocation yourLocation — downloads a file from the server.
server "command" — runs a command remotely, e.g. server myjobs, server "cat file", server "tail file".

function asu(){
    if [ $# -eq 0 ];then
        echo "password\npush\n"|sudo openconnect -u user --server=sslvpn.asu.edu
    elif [ $# -eq 1 ];then
        echo "password\n$1\n"|sudo openconnect -u user --server=sslvpn.asu.edu
    else
        echo "$1\n$2\n"|sudo openconnect -u user --server=sslvpn.asu.edu
    fi
}

The function form only works in zsh; for bash, use the alias form instead:

alias asu='echo "password\npush"|sudo openconnect -u user --server=sslvpn.asu.edu'

Warning

Keeping a password inside .bashrc/.zshrc like this is insecure — treat it as a convenience for a personal, trusted machine only.

Git shortcut

gi(){
    if [ $# -eq 0 ];then
        git pull; git add .; git commit -m "update"; git push;
    elif [ $1 = "commit" ];then
        git add .; git commit -m $2; git push
    elif [ $# -eq 1 ];then
        git clone $1
    fi
}

Quick CMake + Ninja build

alias ninjabuild="cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Release; ninja"

Check a SLURM job's status

checkJob(){
    status=$(squeue -h -j $1 -o "%T")
 
    if [[ -z "$status" ]]; then
        echo "The job $1 has finished"
        return 1
    else
        case $status in
        "RUNNING")
            echo "The job $1 is running"
            return 0
            ;;
        "PENDING")
            echo "The job $1 is pending in queue"
            return 2
            ;;
        *)
            echo "The job $1 is in: $status"
            return 3
            ;;
        esac
    fi
}

Kill jobs by keyword

kill $(ps aux | grep "program Name" | grep "2nd cond if needed" | awk '{print $2}')

The same trick works for GPU jobs shown by nvidia-smi:

kill $(nvidia-smi | grep "program Name" | grep "2nd condititon" | awk '{print $5}')

Misc one-liners

Refresh the timestamp on every file — useful when something automatically purges old files:

find . -type f -exec touch --no-create {} +

Merge files (> overwrites, >> appends):

cat file1 file2 > file3