Conver to -man format; some rewrites; added an EXAMPLE.

man2/syscall.2

@@ -35,34 +35,47 @@
 .\" 2002-03-20  Christoph Hellwig <hch@infradead.org>
 .\"	- adopted for Linux
 .\"
-.Dd June 16, 1993
-.Dt SYSCALL 2
-.Os 4BSD
-.Sh NAME
-.Nm syscall
-.Nd indirect system call
-.Sh SYNOPSIS
-.Fd #include <sys/syscall.h>
-.Fd #include <unistd.h>
-.Ft int
-.Fn syscall "int number" "..."
-.Sh DESCRIPTION
-.Fn Syscall
+.TH SYSCALL 2 2007-06-01 "Linux" "Linux Programmer's Manual"
+.SH NAME
+syscall \- indirect system call
+.SH SYNOPSIS
+.nf
+.B "#define _BSD_SOURCE        /* or _GNU_SOURCE or _SVID_SOURCE */"
+.B #include <unistd.h>
+.B "#include <sys/syscall.h>   /* For SYS_xxx definitons */"
+
+.BI "int syscall(int " number ", ...);"
+.fi
+.SH DESCRIPTION
+.BR syscall ()
 performs the system call whose assembly language
 interface has the specified
-.Fa number
+.I number
 with the specified arguments.
 Symbolic constants for system calls can be found in the header file
-.Ao Pa sys/syscall.h Ac .
-.Sh RETURN VALUE
+.IR <sys/syscall.h> .
+.SH RETURN VALUE
 The return value is defined by the system call being invoked.
 In general, a 0 return value indicates success.
 A \-1 return value indicates an error,
 and an error code is stored in
-.Va errno .
-.Sh HISTORY
-The
-.Fn syscall
-function call appeared in
-.Bx 4.0 .
-.\" dummy comment without newline
+.IR errno .
+.SH NOTES
+.BR syscall ()
+first appeared in
+4BSD.
+.SH EXAMPLE
+
+.nf
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+
+int
+main(int argc, char *argv[])
+{
+    pid_t tid;
+    tid = (long) syscall(SYS_gettid);
+}
+.fi