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Codemonkeying
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Written by Dan
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Thursday, 05 February 2009 12:57 |
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Reasonably often, I have a need to convert an errno variable to its string error message right at the shell. This seems to come up relatively often in kernel development, but occasionally elsewhere. Where I can, I usually just go for a printf("Error: %m\n") or printf("Error: %s\n", strerror(foo)) directly in the debug statement I'm adding. However, %m doesn't work in the kernel and occasionally I either want or have to avoid recompiling something that just prints the integer value. Chasing the header file chain to figure out what a given error code is can be time consuming and silly, but I've done it. Recently, I've been trying to notice when I do stupid things repetitively and take the time to write a helper script or shell alias to prevent wasting effort the next time I need to do a particular task. I have a collection of shell aliases, but I also keep a ~/bin directory with helper scripts for things that fit that mold better. To solve my errno issue, I wrote the following today and stored it in ~/bin/perror: #!/usr/bin/python
import os
import sys
for i in sys.argv[1:]:
i = abs(int(i))
print "%3i: %s" % (i, os.strerror(i))
It could probably be done smaller in a shell alias that calls perl or something, but oh well. This is pretty handy so I can quickly get a couple of values: % perror 111 22
111: Connection refused
22: Invalid argument
I've already used it several times today, so it was definitely worth the 2 minutes it took to codify it.
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