Added a note about write file | read file, which can also create a race condition (and the exception that a non-greedy reader like less is ok).

drevicko
2021-03-25 14:56:23 +11:00
parent a7e31533d5
commit ee29d1febf

@@ -20,6 +20,8 @@ In this case, `grep foo file.txt` will immediately try to read `file.txt` while
This is a race condition, and results in the file being partially or (far more likely) entirely truncated. This is a race condition, and results in the file being partially or (far more likely) entirely truncated.
Note that this can also be a problem when you write to a file and read from it later in the pipe. The second command (which reads the file) may not see all the output of the first. An exception in this case is a non-greedy file reader like `less`, for example `python foo.py 2> errfile.txt | less - errfile.txt` will successfully allow you to see stdout and stderr separately in less.
### Exceptions ### Exceptions
You can ignore this error if: You can ignore this error if: