Bash

Command

See: count-commits

Use following command to count changes in OldPackage from Package create

It is used when port changes from OldPackage to Package

PKG_TIME=$(git log --diff-filter=A --follow --format=%aI --reverse -- "*Package*" | head -1)
echo "Package created at: $PKG_TIME"

filtered_commits=()
while read commit; do
  files=$(git diff-tree --no-commit-id --name-only -r $commit -- "*OldPackage*")
  if echo "$files" | grep -qvE 'OldPackage/Dir/(SubDir1|SubDir2)/'; then
    filtered_commits+=("$commit")
  fi
done < <(git log --since="$PKG_TIME" --format="%H" -- "*OldPackage*")

echo "Commits in OldPackage (excluding Dir/SubDir1 and Dir/SubDir2 only changes): ${#filtered_commits[@]}"

Or

PKG_TIME=$(git log --diff-filter=A --follow --format=%aI --reverse -- "*Package*" | head -1)
echo "Package created at: $PKG_TIME"

count=0
while read commit; do
  files=$(git diff-tree --no-commit-id --name-only -r $commit -- "*OldPackage*")
  if echo "$files" | grep -qvE 'OldPackage/Dir/(SubDir1|SubDir2)/'; then
    ((count++))
  fi
done < <(git log --since="$PKG_TIME" --format="%H" -- "*OldPackage*")

echo "Commits in OldPackage (excluding Dir/SubDir1 and Dir/SubDir2 only changes): $count

Note 1: ${#filtered_commits[@]} is bash array syntax:

• filtered_commits - the array variable name
• [@] - means “all elements in the array”
• ${#...} - the # gets the count/length

So ${#filtered_commits[@]} returns the number of elements in the array.

Note 2: echo "$files" | grep -qvE 'OldPackage/Dir/(SubDir1|SubDir2)/'

• echo "$files" - Output the list of changed files
• | - Pipe to grep
• grep - Search for pattern
• -q - Quiet mode (no output, just exit code)
• -v - Invert match (show lines that DON’T match)
• -E - Extended regex
• 'OldPackage/Dir/(SubDir1|SubDir2)/' - Pattern matching those two Tool directories

Note 3: < <(...) feeds input to the while loop running in the current shell.

Below is error command and should avoid do like this

The issue is that the while read loop runs in a subshell, so the count variable doesn’t persist.

PKG_TIME=$(git log --diff-filter=A --follow --format=%aI --reverse -- "*Package*" | head -1)
echo "Package created at: $PKG_TIME"

count=0
git log --since="$PKG_TIME" --format="%H" -- "*OldPackage*" | while read commit; do
  files=$(git diff-tree --no-commit-id --name-only -r $commit -- "*OldPackage*")
  if echo "$files" | grep -qvE 'OldPackage/Dir/(SubDir1|SubDir2)/'; then
    ((count++))
  fi
done

echo "Commits in OldPackage (excluding Dir/SubDir1 and Dir/SubDir2 only changes): $count

Key note

• command | while - The pipe | creates a subshell for the right side (the while loop)
• while ... < <(command) - Process substitution <(...) creates a temporary file descriptor, and < redirects it as input. The while loop runs in the current shell

Prompt to generate the sample

Give me bash to use git to get time the Package create, then get the numbers of commits in OldPackage since that time. If change only in Dir/SubDir1 or Dir/SubDir2, filter out it. Avoid use `command | while` because The pipe `|` creates a subshell and `while` run in subshell, should use `while ... < <(command)` to make `while` run in current shell