Fixes for zsh/zpty fd message exchange #45
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This was referenced Oct 22, 2020
mafredri
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Oct 23, 2020
This change borrows the idea from #45 to introduce newlines to `zpty -w` as well. Consequently, when we want to properly escape _all_ inputs to `async_job`, we can no longer accept scripts as the first argument, as-is. Furthermore, it was discovered that the current implementation is flawed in the sense that it's impossible to execute a single command where the name or path has spaces in it (how did we not notice this before?). For this reason, `async_job` received the `-s` argument which allows running scripts, for example: async_job myworker -s 'print hello; print world' Whereas a command with spaces can now work without changes: async_job myworker /path/to/my\ executable
mafredri
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Oct 24, 2020
This change borrows the idea from #45 to introduce newlines to `zpty -w` as well. Consequently, when we want to properly escape _all_ inputs to `async_job`, we can no longer accept scripts as the first argument, as-is. Furthermore, it was discovered that the current implementation is flawed in the sense that it's impossible to execute a single command where the name or path has spaces in it (how did we not notice this before?). For this reason, `async_job` received the `-s` argument which allows running scripts, for example: async_job myworker -s 'print hello; print world' Whereas a command with spaces can now work without changes: async_job myworker /path/to/my\ executable
When we output too much data on the zpty fd it can become corrupt in some cases, this commit protects against this by only printing 1024 bytes at a time. Further, when notifying via kill signas, we notify the parent process after every chunk so that the fd can be emptied. In my testing, 1024 bytes seems to be the maximum safe limit that can be used. Perhaps evidence to support this conclusion could be found in the zsh code base.
There seems to be a chance that, when the zpty simultaneously outputs and receives data, the output data is lost. Introducing newlines seems to fix the issue. Simply introducing trailing newlines did not. Reason is not entirely clear, perhaps there is something special about the zpty fd or perhaps this is a property of `zpty -r` / `read`.
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intelfx
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This change borrows the idea from mafredri#45 to introduce newlines to `zpty -w` as well. Consequently, when we want to properly escape _all_ inputs to `async_job`, we can no longer accept scripts as the first argument, as-is. Furthermore, it was discovered that the current implementation is flawed in the sense that it's impossible to execute a single command where the name or path has spaces in it (how did we not notice this before?). For this reason, `async_job` received the `-s` argument which allows running scripts, for example: async_job myworker -s 'print hello; print world' Whereas a command with spaces can now work without changes: async_job myworker /path/to/my\ executable
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Fixes #44.
Maybe fixes #40.
Maybe fixes #18.