1 前言

一个问题，一篇文章，一出故事。
笔者今天遇到一个非标准的sftp客户端，断开连接后留下部分会话进程不能正常释放。
如果使用命令行查看进程，可见如下显示，

ps -eo pid,lstart,cmd | grep sftp | grep will | grep cmdschool.org

可见如下显示，

#...
1416409 Tue Jan 20 15:35:22 2026 sftpd: cmdschool.org\\will [priv]
1416415 Tue Jan 20 15:35:23 2026 sftpd: will@cmdschool.org@notty
1416416 Tue Jan 20 15:35:23 2026 sftpd: will@cmdschool.org@internal-sftp

基于以上问题于是我总结本章的临时解决方案。

2 最佳实践

2.1 测试环境

如何基于Oracle Linux 9.x配置独立的SFTP服务？

2.2 部署监控脚本

2.2.1 创建脚本

vim ~/scripts/killSftpProcess.sh

加入如下配置，

#!/bin/bash

# Config: Target process pattern, username, timeout (1 hour = 3600s)
#processPattern="sftpd: .*@internal-sftp"
#processPattern="sftpd: .*@notty"
processPattern="sftpd: .*\[priv\]"
userName="will"
domainName="cmdschool.org"
timeoutSeconds=86400
logFile="/var/log/sftp/killSftpProcess.log"

# Current timestamp (seconds since epoch)
currentTimestamp=$(date +%s)

# Iterate ps output line by line (IFS = newline)
IFS=$'\n'
psList=$(ps -eo pid,lstart,cmd | grep -E "$processPattern" | grep "$userName" | grep "$domainName")

for psLine in $psList; do
    
    [ -z "$psLine" ] && continue  # Skip empty lines

    # Extract process info (PID, start time, command)
    pid=$(echo "$psLine" | awk '{print $1}')
    lstart=$(echo "$psLine" | awk '{print $2" "$3" "$4" "$5" "$6}')
    cmd=$(echo "$psLine" | awk '{print $7" "$8}')

    # Convert start time to timestamp (suppress errors)
    startTimestamp=$(date -d "$lstart" +%s 2>/dev/null)

    # Calculate runtime and check timeout
    runTime=$((currentTimestamp - startTimestamp))
    if [ "$runTime" -le "$timeoutSeconds" ]; then
	continue
    fi
    runHours=$((runTime/3600))
    runMinutes=$(((runTime%3600)/60))
    echo "$(date +'%Y-%m-%d %H:%M:%S') Process $pid running for $runHours""h $runMinutes""m, terminating" | tee -a "$logFile"
        
    # Kill process (graceful → force)
    kill "$pid" 2>/dev/null || kill -9 "$pid" 2>/dev/null
    echo "----------------------------------------"
done

2.2.2 测试脚本

bash ~/scripts/killSftpProcess.sh

2.2.3 设置脚本触发

*/5 * * * * bash ~/scripts/killSftpProcess.sh