python打印输出通过管道传输到BASH导致“管道中断”

Question

I have a python script that prints to the stdout a list of files, for example:

$ ./myscript.py "file a.txt" "file b.txt" "file c.txt"

I want to open these files in LESS

$ less <(./myscript.py)

But I get the following error:

-bash: /dev/fd/63: Permission denied $ Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'> BrokenPipeError: [Errno 32] Broken pipe

I think it may be the same problem as @Jon-Clements refers to in grep: broken pipe error python 2.2 , ie the pipe is finished; but I'm not sure. I also tried (maybe incorrectly) the solution by @chepner store return value of a Python script in a bash script but it gives the same error.

How can I fix this? I know that mixing BASH and Python is bad practice.

BTW, the python script is using a loop around the following statement to produce the list of filenames:

print('"'+filename+'"',sep=" ",end=' ',) Also, when I copy and paste the output manually to less , it works fine.

Answer 1

Adding quotes around the file name isn't helpful. What you should do is

1. Output each filename will a null byte between them.
2. Pipe the output to xargs -0 .

Quoting the filenames won't help unless you somehow use eval , which is not a good idea for security reasons. Your command should look something like

./myscript.py | xargs -0 less

As a hack, if the filenames are simple (ie no whitespace, no glob characters), you could modify ./myscript.py to output just the space-separated file names (no quotes), then run

less $(myscript.py)

since less only takes filename arguments.

Answer 2

In bash < means redirects a file as standard input, and your python script is not a file.

You can use ./myscript.py | less ./myscript.py | less instead.