sscanf(): Bad scan conversion character "."
Open
Nobody has claimed this yet.
Bug
Extension: standard
Status: Needs Triage
- Dominant language
- C
- Stars
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Description
Description
The following code:
<?php
$format = 'only %d - %.1f';
printf($format, 1, 2);
$str = sprintf($format, 1, 2);
sscanf($str, $format, $low, $max);
Resulted in this output:
only 1 - 2.0
Fatal error: Uncaught ValueError: Bad scan conversion character "." in /in/I1AVe:6
Stack trace:
#0 /in/I1AVe(6): sscanf('only 1 - 2.0', 'only %d - %.1f', NULL, NULL)
#1 {main}
thrown in /in/I1AVe on line 6
But I expected this output instead:
- no error, because shouldn't any format which is not marked as "not supported" in the docs work in both directions?
PHP Version
PHP 8.x
Operating System
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the PHP reproducer and the sscanf() format-parsing entry point; compare its handling of %.1f with the documented printf()/sprintf() behavior. Done means the supported format behavior is resolved consistently and covered by a regression test.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c, php
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100