如何匹配指定模式删除/var/log/script1/日志文件内容并回写至原文件？

Let's walk through how to safely clean up those unwanted stack trace entries from your log files in /var/log/script1/. First off, always back up your files before making any edits—this is a must to avoid accidental data loss.

Step 1: Create a Backup of All Log Files #

First, set up a backup directory and copy all your logs there to keep a safe copy:

mkdir -p /var/log/script1/backup/
cp /var/log/script1/*.log* /var/log/script1/backup/

Step 2: Choose the Right Command for Your Needs #

There are two common scenarios here—pick the one that fits exactly what you want to do:

Scenario 1: Delete Entire Lines Containing "at java.util.conc..." #

If you want to remove the full stack trace line that includes this pattern (the usual case for these log entries), use this batch command to process all files:

for file in /var/log/script1/*.log*; do
  sed -i '/at java\.util\.conc/d' "$file"
done

• Quick breakdown:
  • sed -i: Edits the file in-place (directly modifies the original). If you're on macOS/BSD, use sed -i.bak instead—this creates a backup of each file with a .bak suffix before making changes.
  • /at java\.util\.conc/d: The regex matches any line containing the exact string at java.util.conc (we escape the . because it's a special character in regex), and d tells sed to delete that line entirely.

Scenario 2: Remove Only the "at java.util.conc..." Substring (Keep the Rest of the Line) #

If you want to keep the line but just strip out the stack trace fragment itself, use this substitution command:

for file in /var/log/script1/*.log*; do
  sed -i 's/at java\.util\.conc[^[:space:]]*//g' "$file"
done

• Quick breakdown:
  • s/pattern/replacement/g: Sed's substitution command. The g ensures we replace all occurrences in a line, not just the first one.
  • at java\.util\.conc[^[:space:]]*: Matches at java.util.conc followed by any non-space characters (this captures the full stack trace entry like at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)).
  • //: Replaces the matched text with nothing (effectively deleting it).

Step 3: Test First (Critical!) #

Before running the batch command on all files, test it on one log to confirm it does what you expect:

# Test Scenario 1 (delete full lines)
sed '/at java\.util\.conc/d' /var/log/script1/controller.log | head -20

# Test Scenario 2 (remove only the substring)
sed 's/at java\.util\.conc[^[:space:]]*//g' /var/log/script1/controller.log | head -20

This will show you the first 20 lines of the modified output without touching the original file. Tweak the regex if needed based on what you see.

内容的提问来源于stack exchange，提问作者Akshay