shebang | 易学教程

Shebang Notation: Python Scripts on Windows and Linux?

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I have some small utility scripts written in Python that I want to be usable on both Windows and Linux. I want to avoid having to explicitly invoke the Python interpreter. Is there an easy way to point shebang notation to the correct locations on both Windows and Linux? If not, is there another way to allow implicit invocation of the Python interpreter on both Windows and Linux without having to modify the script when transferring between operating systems? Edit: The shebang support on Windows is provided Cygwin, but I want to use the native Windows Python interpreter on Windows, not the

What does the line “#!/bin/sh” mean in a UNIX shell script?

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问题 I was going through some shell script tutorials and found the following sample program: #!/bin/sh clear echo \"HELLO WORLD\" Can anyone please tell me what the significance of the comment #!/bin/sh at the start is? 回答1: It's called a shebang , and tells the parent shell which interpreter should be used to execute the script. e.g. #!/usr/bin/perl <--perl script' #!/usr/bin/php <-- php script #!/bin/false <--- do-nothing script, because false returns immediately anyways. It's implemented as a

Shebang line limit in bash and linux kernel

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问题 I\'m trying to execute python scripts automatically generated by zc.buildout so I don\'t have control over them. My problem is that the shebang line (#!) is too long for either bash (80 character limit) or direct execution (some Linux kernel constant I don\'t know). This is an example script to help you reproduce my problem: #!/./././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././.

Why is #!/usr/bin/env bash superior to #!/bin/bash?

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问题 I\'ve seen in a number of places, including recommendations on this site (What is the preferred Bash shebang?), to use #!/usr/bin/env bash in preference to #!/bin/bash . I\'ve even seen one enterprising individual suggest using #!/bin/bash was wrong and bash functionality would be lost by doing so. All that said, I use bash in a tightly controlled test environment where every drive in circulation is essentially a clone of a single master drive. I understand the portability argument, though it

What is the difference between “#!/usr/bin/env bash” and “#!/usr/bin/bash”?

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问题 In the header of a bash script, what\'s the difference between those two statements ? #!/usr/bin/env bash #!/usr/bin/bash When I tried to see the env man page, I get this definition: env - run a program in a modified environment What does it mean? 回答1: Running a command through /usr/bin/env has the benefit of looking for whatever the default version of the program is in your current env ironment. This way, you don't have to look for it in a specific place on the system, as those paths may be

Shebang Notation: Python Scripts on Windows and Linux?

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问题 I have some small utility scripts written in Python that I want to be usable on both Windows and Linux. I want to avoid having to explicitly invoke the Python interpreter. Is there an easy way to point shebang notation to the correct locations on both Windows and Linux? If not, is there another way to allow implicit invocation of the Python interpreter on both Windows and Linux without having to modify the script when transferring between operating systems? Edit: The shebang support on

Cannot pass an argument to python with “#!/usr/bin/env python”

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问题 I needed to have a directly executable python script, so i started the file with #!/usr/bin/env python . However, I also need unbuffered output, so i tried #!/usr/bin/env python -u , but that fails with python -u: no such file or directory . I found out that #/usr/bin/python -u works, but I need it to get the python in PATH to support virtual env environments. What are my options? 回答1: It is better to use environment variable to enable this. See python doc : http://docs.python.org/2/using

Why do you need to put #!/bin/bash at the beginning of a script file?

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问题 I have made Bash scripts before and they all ran fine without this at the beginning. What\'s the point of putting it in? Would things be any different? Also, how do you pronounce # ? I know that ! is pronounced as \"bang.\" How is #! pronounced? 回答1: It's a convention so the *nix shell knows what kind of interpreter to run. For example, older flavors of ATT defaulted to sh (the Bourne shell), while older versions of BSD defaulted to csh (the C shell). Even today (where most systems run bash,

What is the preferred Bash shebang?

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问题 Is there any Bash shebang objectively better than the others for most uses? #!/usr/bin/env bash #!/bin/bash #!/bin/sh #!/bin/sh - etc I vaguely recall a long time ago hearing that adding a dash to the end prevents someone passing a command to your script, but can’t find any details on that. 回答1: You should use #!/usr/bin/env bash for portability: different *nixes put bash in different places, and using /usr/bin/env is a workaround to run the first bash found on the PATH . And sh is not bash .

Should I put #! (shebang) in Python scripts, and what form should it take?

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问题 Should I put the shebang in my Python scripts? In what form? #!/usr/bin/env python or #!/usr/local/bin/python Are these equally portable? Which form is used most? Note: the tornado project uses the shebang. On the other hand the Django project doesn\'t. 回答1: The shebang line in any script determines the script's ability to be executed like a standalone executable without typing python beforehand in the terminal or when double clicking it in a file manager (when configured properly). It isn't