bash 从 fcntl 锁定文件中排除循环

Question

我有一个简单的脚本，它遍历文件夹中的文件，然后将它们从 flv 转换为 mp4。如何在 bash 中跳过文件夹中具有 的文件fcntl 锁定它们，然后在解除锁定时返回？

#!/bin/bash


for file in /video_recordings/stream/*.flv; do

  today=`date '+%Y_%m_%d_%H_%M_%S'`;

  cp -v "$file" /video_recordings/stream/backups/$today.flv;

  [ -e "${file%.flv}".mp4 ] || ffmpeg -threads 1 -i "$file" -c:v libx264 -c:a aac -b:v 768k -b:a 96k -vf "scale=720:trunc(ow/a/2)*2" -tune fastdecode -preset ultrafast -crf 25  /video_recordings/stream/temp/$today.mp4

  cp -v /video_recordings/stream/temp/$today.mp4 /video_recordings/stream/vod/$today.mp4

  rm /video_recordings/stream/temp/$today.mp4

  sleep 15s;

  rm "$file";

done

Answer 1

我不太了解fcntl , 但根据 this answer此类锁应由 fuser 列出.如果有东西正在访问文件fuser以状态码 0 退出，否则以 1 退出。
要稍后返回锁定的文件，请使用数组，就像它是一个队列一样:

#!/bin/bash
queue=(/video_recordings/stream/*.flv)
while (( ${#queue[@]} > 0 )); do
  file="${queue[0]}"
  queue=("${queue[@]:1}")
  if fuser -s "$file"; then
    echo "$file in use. Try later."
    queue+=("$file")
    continue
  fi
  # insert commands for conversion of `$file` here
done