Execute command that results from execution of a script whose name is in a variable
来源： https://stackoverflow.com/questions/63660088/execute-command-that-results-from-execution-of-a-script-whose-name-is-in-a-varia
command-substitution
Execute command that results from execution of a script whose name is in a variable
来源： https://stackoverflow.com/questions/63660088/execute-command-that-results-from-execution-of-a-script-whose-name-is-in-a-varia
xargs: command substitution $(…) with pipe doesn't work
问题 I'm trying to write short script, and the following command: echo "aaa111 bbb111" | xargs -I {} echo {} | sed 's/111/222/g' returns aaa222 bbb222 , which is what I expect. I expected the next command: echo "aaa111 bbb111" | xargs -I {} echo $(echo {} | sed 's/111/222/g') to return the same, but it returns aaa111 bbb111 ! Why is that? UPD: What I'm trying to achieve: I have many files like pic30-coff-gcc , pic30-coff-ag , etc, and I need to make a symlink for each file, like pic30-gcc -> pic30
How do I use command substition in Dockerfile
问题 In my Dockerfile I need to use command substition to add some environment variables. I want to set ENV PYTHONPATH /usr/local/$(python3 -c 'from distutils import sysconfig; print(sysconfig.get_python_lib())') but it doesn't work. The result is foo@bar:~$ echo $PYTHONPATH /usr/local/$(python3 -c from distutils import sysconfig; print(sysconfig.get_python_lib())) What's wrong? 回答1: What went wrong The $( ... ) command substitution you attempted is for Bash, whereas the Dockerfile is not Bash. So
How do I use command substition in Dockerfile
问题 In my Dockerfile I need to use command substition to add some environment variables. I want to set ENV PYTHONPATH /usr/local/$(python3 -c 'from distutils import sysconfig; print(sysconfig.get_python_lib())') but it doesn't work. The result is foo@bar:~$ echo $PYTHONPATH /usr/local/$(python3 -c from distutils import sysconfig; print(sysconfig.get_python_lib())) What's wrong? 回答1: What went wrong The $( ... ) command substitution you attempted is for Bash, whereas the Dockerfile is not Bash. So
How do I use command substition in Dockerfile
问题 In my Dockerfile I need to use command substition to add some environment variables. I want to set ENV PYTHONPATH /usr/local/$(python3 -c 'from distutils import sysconfig; print(sysconfig.get_python_lib())') but it doesn't work. The result is foo@bar:~$ echo $PYTHONPATH /usr/local/$(python3 -c from distutils import sysconfig; print(sysconfig.get_python_lib())) What's wrong? 回答1: What went wrong The $( ... ) command substitution you attempted is for Bash, whereas the Dockerfile is not Bash. So
How do I use command substition in Dockerfile
问题 In my Dockerfile I need to use command substition to add some environment variables. I want to set ENV PYTHONPATH /usr/local/$(python3 -c 'from distutils import sysconfig; print(sysconfig.get_python_lib())') but it doesn't work. The result is foo@bar:~$ echo $PYTHONPATH /usr/local/$(python3 -c from distutils import sysconfig; print(sysconfig.get_python_lib())) What's wrong? 回答1: What went wrong The $( ... ) command substitution you attempted is for Bash, whereas the Dockerfile is not Bash. So
How do I use command substition in Dockerfile
问题 In my Dockerfile I need to use command substition to add some environment variables. I want to set ENV PYTHONPATH /usr/local/$(python3 -c 'from distutils import sysconfig; print(sysconfig.get_python_lib())') but it doesn't work. The result is foo@bar:~$ echo $PYTHONPATH /usr/local/$(python3 -c from distutils import sysconfig; print(sysconfig.get_python_lib())) What's wrong? 回答1: What went wrong The $( ... ) command substitution you attempted is for Bash, whereas the Dockerfile is not Bash. So
How to set environment variable within GDB using shell command?
问题 I want to run gdb with only a single variable MyVar in its environment. However, the variable's contents are rather complex, containing non-printable ASCII, and so is best set using e.g. MyVar=$(python -c 'print("\xff...")') . I'm left with two options: Set the MyVar in bash before running gdb . Then inside gdb , remove all other environment variables individually using unset environment NAME ( very tedious! ). Clear all environment variables using unset environment . Then inside gdb , set
How to set environment variable within GDB using shell command?
问题 I want to run gdb with only a single variable MyVar in its environment. However, the variable's contents are rather complex, containing non-printable ASCII, and so is best set using e.g. MyVar=$(python -c 'print("\xff...")') . I'm left with two options: Set the MyVar in bash before running gdb . Then inside gdb , remove all other environment variables individually using unset environment NAME ( very tedious! ). Clear all environment variables using unset environment . Then inside gdb , set