shell functions

For rebase

Often I find the need to squash commits, especially those that don’t need to stand-alone. And so little a function, which is more an alias with arguments, is used for the job, so I don’t have to think. The git command I use for this in, say, master branch, looks like this:

git rebase -i origin/master~4 master

The -i switch makes it interactive, and in the (below) list it produces, I can mark lines selectively from pick to squash for items to be squashed, followed by :wq.¹ If there are multiples marked up in the list, then git produces parent commits with an option to edit commit message(s) should you want to, and you can follow it up with :wq. Here’s an example of the list, in which, one can markup the first column as required.

pick fa77b22 # m:homepage updates
pick 04863ce # link titles update
squash c8fb9a8 # m:edit

# Rebase 69a0567..c8fb9a8 onto 69a0567 (3 commands)
#
# Commands:
# p, pick <commit> = use commit
# r, reword <commit> = use commit, but edit the commit message
# e, edit <commit> = use commit, but stop for amending
# s, squash <commit> = use commit, but meld into previous commit
...

I follow it up with a forced push like so — for sending it upstream. It’s only if the remote already has commits you’re trying to squash.

git push -u origin +master

fish shell

The rebase command feels a little tedious to type out at the prompt, and so this function (placed in ~/.config/fish/config.fish) helps me do the job quickly by running the command gr 4 master, which translates to the first command above:

function gr --description "Rebase e.g. gr 4 master"
    git rebase -i origin/$argv[2]~$argv[1] $argv[2]
end

Using two arguments for the freedom to define the number of commits, and the other being able to choose the branch.

For the push, I could write a function to run gpp master like so:

function gpp --description "Rebased push e.g. gpp master"
    git push -u origin +$argv[1]
end

bash shell

Of course, I have machines where bash is still the default. For those, the function (placed in, e.g., ~/.bashrc) becomes:

# bash function for rebase, e.g., gr 4 master
gr() {
    git rebase -i origin/"${2}~${1}" "$2"
}

And for the push in bash, the function would be:

# bash function for the push post rebase, e.g., gpp master
gpp() {
    git push -u origin +"$1"
}

Pulling from a force-pushed remote repository, say, origin/master needs some care. The right way is as follows:

git fetch origin
git reset --hard origin/master

Fish functions

This is a placeholder for my commonly used fish shell functions — saved as files under ~/.config/fish/functions/.

1. For system information: sbcinf.fish

   function sbcinf --description "Print SBC vitals"
       set -l mem (free -h | awk '/Mem:/ {print $3 "/" $2}')
       set -l dsk (df -h | awk '/\/$/ {print $3 "/" $2}')
       set -l tem (vcgencmd measure_temp | grep -o -E '[[:digit:]].*')
       set -l pow (vcgencmd measure_volts | sed 's/volt=//g')
       set -l ipa (hostname -I | awk '{print $1}')
       set -l upt (uptime -p | sed 's/^up //')
   
       echo "Board temp: $tem"
       echo "Disk usage: $dsk"
       echo "IP address: $ipa"
       echo "Memory use: $mem"
       echo "Power cons: $pow"
       echo "Sys uptime: $upt"
   end
   

2. For downloading a file from GitHub repo. with ghdl user/repo/file.ext. If specific about a branch, then this works too: ghdl user/repo@master/file.ext

   function ghdl --description "Download a file from repo e.g. ghdl user/repo/file.ext"
       if test (count $argv) -ne 1
           echo "Usage: ghdl user/repo[@branch]/path/to/file"
           return 1
       end
   
       set input $argv[1]
   
       # Split the input into repo and path
       set repo_part (echo $input | cut -d'/' -f1-2)
       set path_part (echo $input | cut -d'/' -f3-)
   
       # Extract user and repo (and optional branch)
       set user (echo $repo_part | cut -d'/' -f1)
       set repo_branch (echo $repo_part | cut -d'/' -f2)
   
       if string match -q '*@*' $repo_branch
           set repo (echo $repo_branch | cut -d'@' -f1)
           set branch (echo $repo_branch | cut -d'@' -f2)
       else
           set repo $repo_branch
           set branch "master"  # default fallback branch
       end
   
       if test -z "$user" -o -z "$repo" -o -z "$path_part"
           echo "Error: Must be in the form user/repo[@branch]/path/to/file"
           return 1
       end
   
       # Construct modern raw.githubusercontent.com URL
       set url "https://raw.githubusercontent.com/$user/$repo/refs/heads/$branch/$path_part"
   
       echo "Downloading from: $url"
       curl -LO $url
   end
   

3. Push functions

   function gp --description "Push to remote e.g. gp master"
       git push -u origin $argv[1]
   end
   function gpp --description "Rebase push to remote e.g. gpp bb"
       git push -u origin +$argv[1]
   end
   

4. Rebase function

   function gr --description "Rebase e.g. gr 4 master"
       git rebase -i origin/$argv[2]~$argv[1] $argv[2]
   end
   

5. Get the latest release version of a GitHub repo.

   function glr --description 'Get latest release of a repo e.g. glr "ckunte/tce"' \
       --argument-names user_repo
       curl \
           --silent \
           "https://api.github.com/repos/$user_repo/releases/latest" \
       | string match --regex '"tag_name": "\K.*?(?=")'
   end
   

6. Check file hash

   function check_hashes
       # Ensure the user provided a file argument
       if test (count $argv) -ne 1
           echo "Usage: check_hashes <file>"
           return 1
       end
       # Store the file path
       set file $argv[1]
       # Check if the file exists
       if not test -e $file
           echo "Error: File '$file' does not exist."
           return 1
       end
       echo "RMD160 hash:"
       printf "%s" "$file" | openssl dgst -rmd160
       echo "SHA256 hash:"
       printf "%s" "$file" | openssl dgst -sha256
   end
   

7. Rename photos

   function renfoto --description "Rename photos e.g. renfoto ST-159"
       set prefix $argv[1]
       rename -N ...01 -X -e '$_ = $prefix . "-photo-$N"' *.png
   end
   

8. Toggle WiFi on/off using the custom command beam:

   function beam --description "Toggles Wi-Fi on/off"
       set wifi_status (nmcli radio wifi)
   
       if test "$wifi_status" = "enabled"
           printf "Turning Wi-Fi OFF... "
           nmcli radio wifi off
           printf "done.\n"
       else
           printf "Turning Wi-Fi ON... "
           nmcli radio wifi on
           printf "done.\n"
       end
   end
   

9. Toggle ethernet on/off using the custom command lan:

   function lan --description "Toggles Ethernet (eth0) on/off"
       # Get the current state of eth0
       set eth_status (nmcli -t -f DEVICE,STATE device | grep "^eth0:" | cut -d: -f2)
   
       if test "$eth_status" = "connected"
           nmcli device disconnect eth0
       else
           nmcli device connect eth0
       end
   end