Change things like "NULL-terminated string" to "null-terminated string"

man2/getxattr.2

@@ -83,7 +83,7 @@ is interrogated in place of
 .PP
 An extended attribute
 .I name
-is a simple NULL-terminated string.
+is a simple null-terminated string.
 The name includes a namespace prefix; there may be several, disjoint
 namespaces associated with an individual inode.
 The value of an extended attribute is a chunk of arbitrary textual or

man2/listxattr.2

@@ -57,7 +57,7 @@ retrieves the
 of extended attribute names associated with the given
 .I path
 in the filesystem.
-The list is the set of (NULL-terminated) names, one after the other.
+The list is the set of (null-terminated) names, one after the other.
 Names of extended attributes to which the calling process does not
 have access may be omitted from the list.
 The length of the attribute name
@@ -83,7 +83,7 @@ is interrogated in place of
 .PP
 A single extended attribute
 .I name
-is a simple NULL-terminated string.
+is a simple null-terminated string.
 The name includes a namespace prefix; there may be several, disjoint
 namespaces associated with an individual inode.
 .PP
@@ -95,8 +95,8 @@ size of a buffer which is sufficiently large to hold the list of names.
 .SH EXAMPLES
 The
 .I list
-of names is returned as an unordered array of NULL-terminated character
-strings (attribute names are separated by NULL characters), like this:
+of names is returned as an unordered array of null-terminated character
+strings (attribute names are separated by NUL characters), like this:
 .fam C
 .RS
 .nf

man2/removexattr.2

@@ -72,7 +72,7 @@ only the extended attribute is removed from the open file pointed to by
 in place of
 .IR path .
 .PP
-An extended attribute name is a simple NULL-terminated string.
+An extended attribute name is a simple null-terminated string.
 The
 .I name
 includes a namespace prefix; there may be several, disjoint

man2/rename.2

@@ -91,7 +91,7 @@ or
 .I oldpath
 is a directory and does not allow write permission (needed to update
 the
-.B ..
+.I ..
 entry).
 (See also
 .BR path_resolution (2).)

man2/rmdir.2

@@ -62,7 +62,7 @@ is the current working directory or root directory of some process.
 .B EINVAL
 .I pathname
 has
-.B .
+.I .
 as last component.
 .TP
 .B ELOOP

man2/setxattr.2

@@ -83,7 +83,7 @@ only the extended attribute is set on the open file pointed to by
 in place of
 .IR path .
 .PP
-An extended attribute name is a simple NULL-terminated string.
+An extended attribute name is a simple null-terminated string.
 The
 .I name
 includes a namespace prefix; there may be several, disjoint

man2/symlink.2

@@ -48,7 +48,7 @@ link had been substituted into the path being followed to find a file or
 directory.
 
 Symbolic links may contain
-.B ..
+.I ..
 path components, which (if used at the start of the link) refer to the
 parent directories of that in which the link resides.
 

man3/btree.3

@@ -109,7 +109,7 @@ routine calls with the R_CURSOR flag set will always return the logical
 cachesize
 A suggested maximum size (in bytes) of the memory cache.
 This value is
-.B only
+.I only
 advisory, and the access method will allocate more memory rather than fail.
 Since every search examines the root page of the tree, caching the most
 recently used pages substantially improves access time.
@@ -174,7 +174,7 @@ data sets can produce significantly reduced tree sizes and search times.
 If
 .I prefix
 is NULL (no prefix function is specified),
-.B and
+.I and
 no comparison function is specified, a default lexical comparison routine
 is used.
 If

man3/ether_aton.3

@@ -75,16 +75,16 @@ which subsequent calls will overwrite.
 .PP
 The \fBether_ntohost\fP() function maps an Ethernet address to the
 corresponding hostname in 
-.B /etc/ethers
+.I /etc/ethers
 and returns non-zero if it cannot be found.
 .PP
 The \fBether_hostton\fP() function maps a hostname to the
 corresponding Ethernet address in
-.B /etc/ethers
+.I /etc/ethers
 and returns non-zero if it cannot be found.
 .PP
 The \fBether_line\fP() function parses a line in
-.B /etc/ethers
+.I /etc/ethers
 format (ethernet address followed by whitespace followed by
 hostname; '#' introduces a comment) and returns an address
 and hostname pair, or non-zero if it cannot be parsed.

man3/fopen.3

@@ -171,7 +171,7 @@ Upon successful completion
 and
 .BR freopen ()
 return a
-.B FILE
+.I FILE
 pointer.  Otherwise,
 .B NULL
 is returned and the global variable