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comparison src/memory.rs @ 60:05cc2c27334f

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The Big Refactor: clean up docs and exports. - Brings the most important symbols in the library to the root with `pub use` statements. - Expands and updates documentation. - Rearranges things extensively to make the external interface nicer and make the structure easier to understand. - Renames a few things (e.g. `Result`).
author Paul Fisher <paul@pfish.zone>
date Wed, 21 May 2025 19:00:51 -0400
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children bbe84835d6db
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59:3f4a77aa88be 60:05cc2c27334f
1 //! Utility functions for dealing with memory copying and stuff.
2
3 use crate::ErrorCode;
4 use libc::c_char;
5 use std::ffi::{CStr, CString};
6
7 /// Safely converts a `&str` option to a `CString` option.
8 pub fn option_cstr(prompt: Option<&str>) -> crate::Result<Option<CString>> {
9 prompt
10 .map(CString::new)
11 .transpose()
12 .map_err(|_| ErrorCode::ConversationError)
13 }
14
15 /// Gets the pointer to the given CString, or a null pointer if absent.
16 pub fn prompt_ptr(prompt: Option<&CString>) -> *const c_char {
17 match prompt {
18 Some(c_str) => c_str.as_ptr(),
19 None => std::ptr::null(),
20 }
21 }
22
23 /// Creates an owned copy of a string that is returned from a
24 /// <code>pam_get_<var>whatever</var></code> function.
25 pub fn copy_pam_string(result_ptr: *const c_char) -> crate::Result<String> {
26 // We really shouldn't get a null pointer back here, but if we do, return nothing.
27 if result_ptr.is_null() {
28 return Ok(String::new());
29 }
30 let bytes = unsafe { CStr::from_ptr(result_ptr) };
31 bytes
32 .to_str()
33 .map(String::from)
34 .map_err(|_| ErrorCode::ConversationError)
35 }