6c201db005
Checks for the suspicious use of OpenOptions::create() without an explicit OpenOptions::truncate(). create() alone will either create a new file or open an existing file. If the file already exists, it will be overwritten when written to, but the file will not be truncated by default. If less data is written to the file than it already contains, the remainder of the file will remain unchanged, and the end of the file will contain old data. In most cases, one should either use `create_new` to ensure the file is created from scratch, or ensure `truncate` is called so that the truncation behaviour is explicit. `truncate(true)` will ensure the file is entirely overwritten with new data, whereas `truncate(false)` will explicitely keep the default behavior. ```rust use std::fs::OpenOptions; OpenOptions::new().create(true).truncate(true); ```
63 lines
2.4 KiB
Plaintext
63 lines
2.4 KiB
Plaintext
error: file opened with `truncate` and `read`
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--> $DIR/open_options.rs:7:5
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LL | OpenOptions::new().read(true).truncate(true).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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= note: `-D clippy::nonsensical-open-options` implied by `-D warnings`
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= help: to override `-D warnings` add `#[allow(clippy::nonsensical_open_options)]`
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error: file opened with `append` and `truncate`
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--> $DIR/open_options.rs:10:5
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LL | OpenOptions::new().append(true).truncate(true).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: the method `read` is called more than once
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--> $DIR/open_options.rs:13:5
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LL | OpenOptions::new().read(true).read(false).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: the method `create` is called more than once
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--> $DIR/open_options.rs:15:5
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LL | OpenOptions::new().create(true).create(false).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: file opened with `create`, but `truncate` behavior not defined
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--> $DIR/open_options.rs:15:5
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LL | OpenOptions::new().create(true).create(false).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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= note: `-D clippy::suspicious-open-options` implied by `-D warnings`
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= help: to override `-D warnings` add `#[allow(clippy::suspicious_open_options)]`
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error: the method `write` is called more than once
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--> $DIR/open_options.rs:17:5
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LL | OpenOptions::new().write(true).write(false).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: the method `append` is called more than once
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--> $DIR/open_options.rs:19:5
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LL | OpenOptions::new().append(true).append(false).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: the method `truncate` is called more than once
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--> $DIR/open_options.rs:21:5
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LL | OpenOptions::new().truncate(true).truncate(false).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: file opened with `create`, but `truncate` behavior not defined
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--> $DIR/open_options.rs:23:5
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LL | OpenOptions::new().create(true).open("foo.txt");
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: aborting due to 9 previous errors
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