Context:

上下文：

I want to add a conditional startup script to LightDM that detects screen resolution and if it is too high, it scales the screen via xrandr.

我想给LightDM添加一个有条件的启动脚本，它可以检测屏幕分辨率，如果分辨率太高，它会通过xrandr来缩放屏幕。

Script (irrelevant to this question):

脚本(与此问题无关)：

#!/bin/bash

# If the display has higher resolution than X_THR x Y_THR,
# it will be scaled by a factor of SCALE x SCALE.
X_THR=3840
Y_THR=2160
SCALE=0.5

# First, check if exactly one display is connected.
# Otherwise, we don't really know what's happening and
# the script should terminate without making changes.
if [ "$(xrandr | grep -w connected | wc -l)" -ne 1 ];
then
  echo "Not adjusting screen settings automatically,\
        detected $(xrandr | grep -w connected | wc -l)\
        screens";
  exit 0;
fi

# Note that the screen may either be marked as "primary"
# or not. By treating "primary" as a field separator in AWK
# we handle both cases.
read display_name resolution <<<\
  "$(xrandr | grep -w connected | awk -F'\\sprimary\\s|[ \\+]' '{print $1,$3}')"

read x_dim y_dim <<<\
  "$(echo $resolution | awk -F'x' '{print $1,$2}')"

if [ "$x_dim" -ge "$X_THR" -a "$y_dim" -ge "$Y_THR" ];
then
  echo "Updating X server scale."
  xrandr --output $display_name --scale "$SCALE"x"$SCALE"
fi

LightDM configuration file (/etc/lightdm/lightdm.conf.d/99-labdoo.conf):

LightDM配置文件(/etc/lightdm/lightdm.con.d/99-Labdoo.conf)：

[Seat:*]
user-session=LXDE
display-setup-script=/opt/labdoo/setup/startup_scripts/screen_scaling.sh || true

What happened:

发生的事情：

By a mistake, I changed the preamble in the script from #!/bin/bash to #!/bin/sh, which resulted in the script failing with some syntax error.

由于错误，我将脚本中的前言从#！/bin/bash更改为#！/bin/sh，这导致脚本失败，并出现一些语法错误。

Expected behaviour:
I would expect LightDM to ignore the failure of the script thanks to the || true in display-setup-script.

预期行为：我希望LightDM忽略脚本失败，这要归功于Display-Setup-SCRIPT中的||TRUE。

Actual behaviour:
LightDM failed to load the greeting screen. In /var/log/lightdm/lightdm.log I saw a line:
Exit status of /opt/labdoo/setup/startup_scripts/screen_scaling.sh || true: 1

实际行为：LightDM无法加载问候屏幕。在/var/log/lightdm/lightdm. log中，我看到一行：退出/opt/labdoo/setup/startup_scripts/screen_scaling. sh的状态||真：1

How can the exit status be 1?

退出状态怎么可能是%1？