Modernise the language at the start, speaking of "magic patterns"

rather than "magic numbers". We still mention these later in an
historical context.

Be more consistent in syntax of magic fragments.

diff --git a/doc/magic.man b/doc/magic.man
index f8789a96144a89af2e33ef0d6467fe6e89749f43..d8466ba9418ebc1dcfc1639e6608b47a06580953 100644 (file)
--- a/doc/magic.man
+++ b/doc/magic.man
@@ -1,11 +1,11 @@
-.\" $File: magic.man,v 1.50 2008/02/18 18:28:51 rrt Exp $
+.\" $File: magic.man,v 1.51 2008/02/18 18:32:31 rrt Exp $
 .Dd January 10, 2007
 .Dt MAGIC __FSECTION__
 .Os
 .\" install as magic.4 on USG, magic.5 on V7 or Berkeley systems.
 .Sh NAME
 .Nm magic
-.Nd file command's magic number file
+.Nd file command's magic pattern file
 .Sh DESCRIPTION
 This manual page documents the format of the magic file as
 used by the
@@ -15,12 +15,12 @@ The
 .Xr file __CSECTION__
 command identifies the type of a file using,
 among other tests,
-a test for whether the file begins with a certain
-.Dq "magic number" .
+a test for whether the file contains certain
+.Dq "magic patterns" .
 The file
 .Pa __MAGIC__
-specifies what magic numbers are to be tested for, what message or
-MIME type to print if a particular magic number is found,
+specifies what patterns are to be tested for, what message or
+MIME type to print if a particular pattern is found,
 and additional information to extract from the file.
 .Pp
 Each line of the file specifies a test to be performed.
@@ -151,7 +151,9 @@ A regular expression match in extended POSIX regular expression syntax
 (much like egrep). Regular expressions can easily take exponential
 time to process; their use is discouraged. When used in production
 environments, their performance should be carefully checked. The type
-specification can be optionally followed by /[c][s]. The
+specification can be optionally followed by
+.Dv /[c][s] .
+The
 .Dq c
 flag makes the match case insensitive, while the
 .Dq s
@@ -172,10 +174,10 @@ not beginning and end of file.
 A literal string search starting at the given offset. The same
 modifier flags can be used as for string patterns. The modifier flags
 (if any) must be followed by
-.Dv /\*[Lt]number\*[Gt]
-which specifies how many matches shall be attempted (the range).
-This is suitable for searching larger binary expressions with variable
-offsets, using
+.Dv /number
+the range, that is, the number of positions at which the match will be
+attempted, starting from the start offset. This is suitable for
+searching larger binary expressions with variable offsets, using
 .Dv \e
 escapes for special characters. The offset works as for regex.
 .It Dv default
@@ -245,8 +247,8 @@ is octal, and
 .Dv 0x13
 is hexadecimal.
 .Pp
-For string values, the byte string from the
-file must match the specified byte string.
+For string values, the string from the
+file must match the specified string.
 The operators
 .Dv = ,
 .Dv \*[Lt]
@@ -257,10 +259,10 @@ and
 can be applied to strings.
 The length used for matching is that of the string argument
 in the magic file.
-This means that a line can match any string, and
-then presumably print that string, by doing
+This means that a line can match any non-empty string (usually used to
+then print the string), with
 .Em \*[Gt]\e0
-(because all strings are greater than the null string).
+(because all non-empty strings are greater than the empty string).
 .Pp
 The special test
 .Em x
@@ -364,7 +366,7 @@ there is neither PE\e0\e0 nor LE\e0\e0 in the above example)
 .Pp
 If this indirect offset cannot be used as-is, there are simple calculations
 possible: appending
-.Em [+-*/%\*[Am]|^]\*[Lt]number\*[Gt]
+.Em [+-*/%\*[Am]|^]number
 inside parentheses allows one to modify
 the value read from the file before it is used as an offset:
 .Bd -literal -offset indent
@@ -476,4 +478,4 @@ a system on which the lengths are invariant.
 .\" the changes I posted to the S5R2 version.
 .\"
 .\" Modified for Ian Darwin's version of the file command.
-.\" @(#)$Id: magic.man,v 1.51 2008/02/18 18:32:31 rrt Exp $
+.\" @(#)$Id: magic.man,v 1.52 2008/02/28 13:14:26 rrt Exp $