Hey there! Let's tackle this 2019 code stats task—you don't need those random unfiltered scripts; Git has all the tools you need built right in. Here's a step-by-step breakdown to get exactly what you're after:

This command will calculate the total lines added, removed, and net change across all 2019 commits:

git log --all --since="2019-01-01" --until="2019-12-31" --pretty=tformat: --numstat | awk '{ add += $1; subs += $2; loc += $1 - $2 } END { printf "Total lines added: %s\nTotal lines removed: %s\nTotal net lines: %s\n", add, subs, loc }'

Let me break this down:

• --all: Checks all branches (remove this if you only want a specific branch like main)
• --since/--until: Locks the date range to exactly 2019
• --numstat: Outputs a line with added/removed lines for each file in every commit
• The awk script sums up all the numbers to give you total stats

To get a breakdown per team member, use this command—it will show net lines, added lines, and removed lines for each contributor:

git log --all --since="2019-01-01" --until="2019-12-31" --pretty=tformat: --numstat | awk '{ users[$3] += $1 - $2; add[$3] += $1; sub[$3] += $2 } END { for (user in users) { printf "%s:\n  Net lines: %s\n  Lines added: %s\n  Lines removed: %s\n", user, users[user], add[user], sub[user] } }'

Key notes here:

• $3 grabs the committer's name from the numstat output
• We use associative arrays in awk to accumulate stats per user
• The final loop prints a clean breakdown for each person

• Fix username inconsistencies: If team members used different emails/usernames (e.g., "John Doe" vs "jdoe"), create a .mailmap file in your repo root to unify them. Example:

  John Doe <john.doe@company.com> jdoe <jdoe@old-email.com>
  

  Git will use the first name/email for stats after this.
• Exclude auto-generated files: Skip folders like node_modules, dist, or log files by adding -- . ':!node_modules' ':!dist' to the end of your git log command. Example:

  git log --all --since="2019-01-01" --until="2019-12-31" --pretty=tformat: --numstat -- . ':!node_modules' ':!dist' | awk ...
  

• Filter by specific branches: Replace --all with branch names (e.g., --main --develop) if you don't want to include feature branches that never merged.

内容的提问来源于stack exchange，提问作者Matt