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:

# fish function to rebase, e.g., gr 4 master
function gr
  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:

# fish function for push following rebase, e.g., gpp master
function gpp
  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

   # sbcinf.fish
   function sbcinf
     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

   # ghdl.fish
   function ghdl
     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

   # push function
   #   gp master // normal push to master repo
   #   gpp bb    // rebased push to bb repo
   #
   function gp
     git push -u origin $argv[1]
   end
   function gpp
     git push -u origin +$argv[1]
   end
   

4. Rebase function

   # gr.fish
   # examples:
   #   gr 4 master
   #   gr 3 bb
   #
   function gr
     git rebase -i origin/$argv[2]~$argv[1] $argv[2]
   end
   

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

   # glr.fish
   # e.g. glr "ckunte/tce"
   function glr \
     --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

   # check_hashes.fish
   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
     # Calculate and display the RMD160 hash
     echo "RMD160 hash:"
     printf "%s" "$file" | openssl dgst -rmd160
     # Calculate and display the SHA256 hash
     echo "SHA256 hash:"
     printf "%s" "$file" | openssl dgst -sha256
   end
   

7. Open folder from within WSL

   # open.fish
   function open
     if test (count $argv) -eq 0
       # No arguments: open current directory
       explorer.exe .
     else
       for arg in $argv
         # If it's a URL
         if string match -qr '^https?://|^mailto:' $arg
           explorer.exe $arg
         # If it's a file or directory that exists
         else if test -e $arg
           explorer.exe (wslpath -w $arg)
         # If it's a Windows-style path (C:\Users\...), try passing directly
         else if string match -qr '^[A-Za-z]:\\' $arg
           explorer.exe $arg
         else
           echo "open: '$arg' not found or invalid" >&2
         end
       end
     end
   end
   

8. Rename photos

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