about summary refs log tree commit diff homepage
diff options
context:
space:
mode:
-rw-r--r--crc32.352
l---------crc32_z.31
2 files changed, 53 insertions, 0 deletions
diff --git a/crc32.3 b/crc32.3
new file mode 100644
index 0000000..66191fd
--- /dev/null
+++ b/crc32.3
@@ -0,0 +1,52 @@
+.Dd November 8, 2018
+.Dt CRC32 3
+.Os
+.
+.Sh NAME
+.Nm crc32 ,
+.Nm crc32_z
+.Nd update CRC-32 checksum
+.
+.Sh LIBRARY
+.Lb libz
+.
+.Sh SYNOPSIS
+.In zlib.h
+.Ft uLong
+.Fn crc32 "uLong crc" "const Bytef *buf" "uInt len"
+.Ft uLong
+.Fn crc32_z "uLong crc" "const Bytef *buf" "z_size_t len"
+.
+.Sh DESCRIPTION
+Update a running CRC-32 with the bytes
+.Fa "buf[0..len-1]"
+and return the updated CRC-32.
+If
+.Fa buf
+is
+.Dv Z_NULL ,
+this function returns
+the required initial value for the CRC.
+Pre- and post-conditioning
+(one's complement)
+is performed within this function
+so it shouldn't be done
+by the application.
+.
+.Pp
+.Fn crc32_z
+is the same as
+.Fn crc32 ,
+but with a
+.Vt size_t
+length.
+.
+.Sh EXAMPLES
+.Bd -literal -offset indent
+uLong crc = crc32(0L, Z_NULL, 0);
+
+while (read_buffer(buffer, length) != EOF) {
+	crc = crc32(crc, buffer, length);
+}
+if (crc != original_crc) error();
+.Ed
diff --git a/crc32_z.3 b/crc32_z.3
new file mode 120000
index 0000000..cd5bed9
--- /dev/null
+++ b/crc32_z.3
@@ -0,0 +1 @@
+crc32.3
\ No newline at end of file