脚本中的源.bashrc无法正常工作 [英] source .bashrc in a script not working

问题描述

我正在执行一个脚本，该脚本正在安装ros，并在安装后用catkin_make编译工作区.

我找到了解决问题的解决方案，但我无法解释原因.我有一个名为install.bash的文件正在调用其他文件:

#!/bin/bash

source 01_install_ros.bash

重要的是在01_install_ros.bash中:

# variable not set because it is done in the script setup.bash of ros
echo "before source in 01_install_ros"
echo "ROS_ROOT: "$ROS_ROOT
whereis catkin_make
echo ""

echo "source /opt/ros/kinetic/setup.bash" >> $HOME/.bashrc
# doesn't set the variables
source "$HOME"/.bashrc
# the solutions
source /opt/ros/kinetic/setup.bash

# variables not set if I use the source of .bashrc
echo "after source in 01_install_ros"
echo "ROS_ROOT: "$ROS_ROOT
whereis catkin_make
echo ""

如评论中所述，采购.bashrc而不是直接安装setup.bash无效.我真的不明白为什么.你能解释一下我吗?

解决方案

某些平台附带的~/.bashrc顶部带有一个条件，如果发现外壳不是 non，则该条件明确停止处理-interactive .

例如，在Ubuntu 18.04上:

 # If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac
 

类似的测试，在同一平台上的/etc/bash.bashrc中看到:

# If not running interactively, don't do anything
[ -z "$PS1" ] && return

在这种情况下，从脚本中获取~/.bashrc无效，因为脚本在非交互式外壳中运行默认情况下.

您的选项为:

• 其中之一:停用~/.bashrc

中的条件

• 或者:在调用source ~/.bashrc之前尝试模拟交互式shell .
  所需的具体仿真取决于条件的具体情况，但是有两种可能的方法:如果您不提前知道会遇到什么条件，则可能必须同时雇用他们

  • set -i暂时使$-包含i，表示交互式外壳.
  • 如果您知道执行交互性测试的行的内容，请使用grep将其从~/.bashrc中过滤出来，然后使用eval得出结果(通常应避免使用后者，但应将其放入这种情况有效地提供了与采购相同的功能.
    请注意，确保环境变量PS1的值 还不够，因为Bash 在非交互式shell中主动重置-请参见

或者，如果您控制自己的脚本的调用方式，则可以使用
bash -i script调用它.

I am doing a script that is installing ros and after installing it, compiling a workspace with catkin_make.

I found the solution to solve my problem but I can't explain the reason. I have a file called install.bash that is calling others:

#!/bin/bash

source 01_install_ros.bash

What is important is in 01_install_ros.bash:

# variable not set because it is done in the script setup.bash of ros
echo "before source in 01_install_ros"
echo "ROS_ROOT: "$ROS_ROOT
whereis catkin_make
echo ""

echo "source /opt/ros/kinetic/setup.bash" >> $HOME/.bashrc
# doesn't set the variables
source "$HOME"/.bashrc
# the solutions
source /opt/ros/kinetic/setup.bash

# variables not set if I use the source of .bashrc
echo "after source in 01_install_ros"
echo "ROS_ROOT: "$ROS_ROOT
whereis catkin_make
echo ""

As written in comments, sourcing .bashrc instead of directly setup.bash doesn't work. I really don't get why. Can you explain me?

解决方案

Some platforms come with a ~/.bashrc that has a conditional at the top that explicitly stops processing if the shell is found to be non-interactive.

For example, on Ubuntu 18.04:

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

A similar test, seen in /etc/bash.bashrc on the same platform:

# If not running interactively, don't do anything
[ -z "$PS1" ] && return

If this is the case, sourcing ~/.bashrc from a script will have no effect, because scripts run in non-interactive shells by default.

Your options are:

• Either: deactivate the conditional in ~/.bashrc

• Or: Try to to emulate an interactive shell before invoking source ~/.bashrc.
  The specific emulation needed depends on the specifics of the conditional, but there are two likely approaches; you may have to employ them both if you don't know ahead of time which conditional you'll encounter:

  • set -i temporarily to make $- contain i, indicating an interactive shell.
  • If you know the contents of the line that performs the interactivity test, filter it out of the ~/.bashrc using grep, and then source the result with eval (the latter should generally be avoided, but it in this case effectively provides the same functionality as sourcing).
    Note that making sure that environment variable PS1 has a value is not enough, because Bash actively resets it in non-interactive shells - see this answer for background information.
    • eval "$(grep -vFx '[ -z "$PS1" ] && return' ~/.bashrc)"

Alternatively, if you control how your own script is invoked, you can invoke it with
bash -i script.

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