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| posix_shell_getpots [2019/09/30 11:02] – [Starting points] rpjday | posix_shell_getpots [2019/09/30 12:16] (current) – [Starting points] rpjday |
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| First, there has been much blood spilled discussing how to support //optional// arguments using ''getopts'' -- the correct solution is to not do that, as explained in Guideline 7 [[https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_02|here]]. So we won't. | First, there has been much blood spilled discussing how to support //optional// arguments using ''getopts'' -- the correct solution is to not do that, as explained in Guideline 7 [[https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_02|here]]. So we won't. |
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| And, second, if the //optstring// handed to getopts starts with a colon, then getopts uses what is called "silent error reporting"; this appears to be the recommended approach, so we'll stick with that. If you choose differently, you're on your own. | And, second, if the //optstring// handed to getopts starts with a colon, then getopts uses what is called "silent error reporting"; this appears to be the recommended approach, so we'll stick with that. In short, don't do this: |
| | |
| | <code> |
| | while getopts ab:c: opt ; do |
| | </code> |
| | |
| | Do this (note the leading colon): |
| | |
| | <code> |
| | while getopts :ab:c: opt ; do |
| | </code> |
| | |
| | Explanation below. |
| | |
| | ===== Fleshed out example ===== |
| | |
| | <code> |
| | ... coming soon ... |
| | </code> |