括号在简单的bash行中丢失错误? [英] Bracket missing error in simple bash line?

问题描述

我的bash脚本中的以下两行:

The following 2 lines in my bash script:

fail_str=$'Checking...\nChecking...'
if [ tail -1 /home/pi/video_buffer_usage.txt | grep '100% full' ] || [ tail -2 $out_file | grep "$fail_str" ] ; then

给出错误:

./joi_main.sh: line 63: [: missing `]'
grep: ]: No such file or directory

他们怎么了?

推荐答案

丢掉[] s:

if tail -1 /home/pi/video_buffer_usage.txt | grep '100% full' ||
  tail -2 "$out_file" | grep "$fail_str" ; then

(为可读性添加了无害的换行符)

(added harmless newline for readability)

您可能还想使grep s静音:

you may also then want to silence the greps:

if tail -1 /home/pi/video_buffer_usage.txt | grep -q '100% full' ||
  tail -2 "$out_file" | grep -q "$fail_str" ; then

这篇关于括号在简单的bash行中丢失错误?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！