diff options
Diffstat (limited to 'meap/meap-code/ch6/ch6-memscan-1')
| -rw-r--r-- | meap/meap-code/ch6/ch6-memscan-1/Cargo.lock | 4 | ||||
| -rw-r--r-- | meap/meap-code/ch6/ch6-memscan-1/Cargo.toml | 6 | ||||
| -rw-r--r-- | meap/meap-code/ch6/ch6-memscan-1/src/main.rs | 14 |
3 files changed, 24 insertions, 0 deletions
diff --git a/meap/meap-code/ch6/ch6-memscan-1/Cargo.lock b/meap/meap-code/ch6/ch6-memscan-1/Cargo.lock new file mode 100644 index 0000000..622c46c --- /dev/null +++ b/meap/meap-code/ch6/ch6-memscan-1/Cargo.lock @@ -0,0 +1,4 @@ +[[package]] +name = "ch6-memscan-1" +version = "0.1.0" + diff --git a/meap/meap-code/ch6/ch6-memscan-1/Cargo.toml b/meap/meap-code/ch6/ch6-memscan-1/Cargo.toml new file mode 100644 index 0000000..9819069 --- /dev/null +++ b/meap/meap-code/ch6/ch6-memscan-1/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "ch6-memscan-1" +version = "0.1.0" +authors = ["Tim McNamara <code@timmcnamara.co.nz>"] + +[dependencies] diff --git a/meap/meap-code/ch6/ch6-memscan-1/src/main.rs b/meap/meap-code/ch6/ch6-memscan-1/src/main.rs new file mode 100644 index 0000000..b92da20 --- /dev/null +++ b/meap/meap-code/ch6/ch6-memscan-1/src/main.rs @@ -0,0 +1,14 @@ +fn main() { + let mut n_nonzero = 0; + + for i in 0..10000 { + let ptr = i as *const u8; // <1> Convert `i` to a `pass:[*const T]`, a "`raw pointer`" of type `u8`. Raw pointers allow programmers to inspect raw memory addresses. We treat every address as a unit, ignoring the fact that most values span multiple bytes. + let byte_at_addr = unsafe { *ptr }; // <2> _Dereference_ the pointer. That is, read the value at address `i`. Another way of saying this is read the value being pointed to. + + if byte_at_addr != 0 { + n_nonzero += 1; + } + } + + println!("non-zero bytes in memory: {}", n_nonzero); +}
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