tricks using vim, bash, awk, sed, screen, etc.

• VIM

search/replace on selected/visual area/test

'<,'>s/\%V\ /\,0x/g
:version        # show misc info
:scriptnames    # show init scripts loaded


#Insert sequence
g/$/s//\=line('.')
g/^/s//\=line('.')
g/wqc/s//\=line('.')
g/wqc/s//\=line('.')-14/


set foldmethod=syntax
set foldmethod=indent
set foldnestmax=10
set nofoldenable
set foldlevel=2
set foldcolumn=4

• Screen

#quit screen and terminate all session in it
screen -X -S screen_name quit

• AWK

#remove dup without sort:
awk '!a[$0]++' file

• CMAKE

#cmake compile_commands.json
-DCMAKE_EXPORT_COMPILE_COMMANDS=True

• Bash

#check if bash script is sourced
(return 0 2>/dev/null) && sourced=1 || sourced=0

#Colors:        https://www.cnblogs.com/unclemac/p/12783387.html

renice {
    #!/bin/sh


    if [[ x$1 = x--wrap ]]; then
      echo "my pid: $$"
      echo "params: $@"
      shift
      renice -n -20 -p $$
      exe=$(realpath $0)
      exec $exe $@
    fi


    echo "my pid x: $$"
    echo "params: $@"
}

• Git

git push origin --delete BranchName
git push origin feature-branch:feature-branch
git clone -b  --single-branch

# disable core.compression
git config --global core.compression 0

# clone only head
git clone --depth 1 url

# fetch all
git fetch --unshallow

# check with pull
git pull --all

fix 'unable to update local ref' {
    git gc --prune=now
    git pull
    git remote prune origin
}


git show-branch --merge-base
git merge-base branch2 branch3

• WSL when VPN

#
wsl network when vpn {
    #ref: https://blog.csdn.net/whuisland/article/details/125026163
    #ref: 


    set metrics by admin@powershell {
        Get-NetAdapter | Where-Object {$_.InterfaceDescription -Match "Cisco AnyConnect"} | Set-NetIPInterface -InterfaceMetric 6000
        Get-NetIPInterface -InterfaceAlias "vEthernet (WSL)" | Set-NetIPInterface -InterfaceMetric 1
    }


    ##The InterfaceMetric is a value associated with each adapter that determines the order of those adapters. This allows windows to determine which adapter to prefer over another one.


    ##By setting the interface metric of the Cisco adapter to 4000 and the metric of the WSL adapter to one, we allow the traffic from WSL to flow through the Cisco adapter. To be honest I do not exactly understand why this works but it does.


    get_anyconnect_dns() {
        local DNS_L=""
        local L=""
        local flg=0
        while read L; do
            if [[ flg -eq 0 ]]; then
                if [[ x"$L" =~ x.*AnyConnect.*Adapter.* ]]; then
                    flg=1
                fi
                continue
            fi


            if [[ flg -eq 1 ]]; then
                if [[ x"$L" =~ x.*DNS[[:space:]]+Server.*:[[:space:]]*([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+).* ]]; then
                    flg=2
                    DNS_L=${BASH_REMATCH[1]}
                fi
                continue
            fi


            if [[ flg -eq 2 ]]; then
                if [[ x"$L" =~ ^x[[:space:]]*([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+).* ]]; then
                    DNS_L="$DNS_L ${BASH_REMATCH[1]}"
                fi
                break
            fi


        done


        echo $DNS_L
    }


    {
        echo '[network]'
        echo 'generateResolvConf = false'
    } > /etc/wsl.conf


    for d in $(/mnt/c/Windows/system32//ipconfig.exe /all |tr -d '\r' |get_anyconnect_dns); do
        echo "nameserver $d"
    done > /etc/resolv.conf


}

• ffmpeg

#
ffmpeg {
    for f in *.png; do
        ##apng -> gif
        ffmpeg -i $f -f apng $f.gif


        ##scale to 0.5 and reserve transparency
        ffmpeg -i $f.gif -filter_complex \
        "[0:v] scale=iw/2:ih/2:flags=neighbor,split [a][b]; [a] palettegen=reserve_transparent=on:transparency_color=ffffff [p]; [b][p] paletteuse" ${f}2.gif
    done


    ffmpeg -i $f -vf "scale=iw/2:ih/2" ${f/.gif/}2.gif


    #compress
    ffmpeg -y -i 2_input.mp4 -c:a copy -c:v libx264 -profile:v high -r 30 -crf 30 -b:v 200k -s 1920x1080 -movflags +faststart 2_output.mp4 -hwaccel cuvid -threads 4

    #embed subtitle    
				
					 
				
    ffmpeg.exe -i C:\Users\qingc\Desktop\菜根谭.mp4 -i C:\Users\qingc\Desktop\ 菜根谭.vtt -c:s mov_text -c:v copy -c:a copy cai-gen-tan.mp4
}

        学者以多方丧生
        大道以歧路亡羊
        佛者觉，菩萨者识
        做佛容易，做菩萨难
        根本智易得，差别智难求
        离一切诸相，即名诸佛
        能施一切法，名诸菩萨