Added Cygwin build support

strverscmp is included to satisfy a dependency in Cygwin.
Excluded utmp and prctl functions that are not supported currently.

Makefile.am

@@ -1,3 +1,8 @@
+CYGWINFLAGS =
+if CYGWIN
+  CYGWINFLAGS += -lintl
+endif
+
 AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
 	-I$(top_srcdir) \
@@ -14,7 +19,7 @@ SUBDIRS = \
 	testsuite
 
 AM_CFLAGS = -Iproc
-LDADD = ./proc/libprocps.la
+LDADD = ./proc/libprocps.la $(CYGWINFLAGS)
 
 transform = s/pscommand/ps/; $(program_transform_name)
 
@@ -97,7 +102,7 @@ dist_man_MANS += \
 slabtop_SOURCES = slabtop.c lib/strutils.c lib/fileutils.c
 slabtop_LDADD = $(LDADD) @NCURSES_LIBS@
 watch_SOURCES = watch.c lib/strutils.c lib/fileutils.c
-watch_LDADD = @WATCH_NCURSES_LIBS@
+watch_LDADD = @WATCH_NCURSES_LIBS@ $(CYGWINFLAGS)
 top_top_SOURCES = \
 	top/top.h \
 	top/top.c \
@@ -105,6 +110,10 @@ top_top_SOURCES = \
 	top/top_nls.c \
 	lib/fileutils.c \
 	lib/signals.c
+if CYGWIN
+  top_top_SOURCES += lib/strverscmp.c
+endif
+
 top_top_LDADD = $(LDADD) @NCURSES_LIBS@ $(DL_LIB)
 endif
 
@@ -128,7 +137,7 @@ pgrep_SOURCES = pgrep.c lib/fileutils.c lib/signals.c
 pkill_SOURCES = pgrep.c lib/fileutils.c lib/signals.c
 pmap_SOURCES = pmap.c lib/fileutils.c
 pwdx_SOURCES = pwdx.c lib/fileutils.c
-pwdx_LDADD=
+pwdx_LDADD= $(CYGWINFLAGS)
 sysctl_SOURCES = sysctl.c lib/fileutils.c
 sysctl_LDADD=
 tload_SOURCES = tload.c lib/strutils.c lib/fileutils.c
@@ -245,18 +254,20 @@ check_PROGRAMS = \
 	lib/test_strtod_nol
 
 lib_test_strutils_SOURCES = lib/test_strutils.c lib/strutils.c
-lib_test_strutils_LDADD =
+lib_test_strutils_LDADD = $(CYGWINFLAGS)
 lib_test_fileutils_SOURCES = lib/test_fileutils.c lib/fileutils.c
-lib_test_fileutils_LDADD =
+lib_test_fileutils_LDADD = $(CYGWINFLAGS)
+lib_test_nsutils_SOURCES = lib/test_nsutils.c lib/nsutils.c
+lib_test_nsutils_LDADD = $(CYGWINFLAGS)
 lib_test_process_SOURCES = lib/test_process.c
-lib_test_process_LDADD =
+lib_test_process_LDADD = $(CYGWINFLAGS)
 
 proc_test_sysinfo_SOURCES = proc/test_sysinfo.c
 proc_test_sysinfo_LDADD = proc/libprocps.la
 proc_test_namespace_SOURCES = proc/test_namespace.c
 proc_test_namespace_LDADD = proc/libprocps.la
 lib_test_strtod_nol_SOURCES = lib/test_strtod_nol.c lib/strutils.c
-lib_test_strtod_nol_LDADD =
+lib_test_strtod_nol_LDADD = $(CYGWINFLAGS)
 
 if EXAMPLE_FILES
 sysconf_DATA = sysctl.conf

configure.ac

@@ -168,6 +168,7 @@ AC_ARG_ENABLE([kill],
 )
 AM_CONDITIONAL(BUILD_KILL, test "x$enable_kill" = xyes)
 AM_CONDITIONAL(LINUX, test "x$host_os" = xlinux-gnu)
+AM_CONDITIONAL(CYGWIN, test "x$host_os" = xcygwin)
 
 AC_ARG_ENABLE([skill],
   AS_HELP_STRING([--enable-skill], [build skill and snice]),

lib/strverscmp.c

@@ -0,0 +1,158 @@
+/* Compare strings while treating digits characters numerically.
+   Copyright (C) 1997, 2002, 2005 Free Software Foundation, Inc.
+   This file is part of the libiberty library.
+   Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
+
+   Libiberty is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   Libiberty is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.  */
+
+/* #include "libiberty.h" */
+/* #include "safe-ctype.h" */
+#include <ctype.h>
+
+/* 
+@deftypefun int strverscmp (const char *@var{s1}, const char *@var{s2})
+The @code{strverscmp} function compares the string @var{s1} against
+@var{s2}, considering them as holding indices/version numbers.  Return
+value follows the same conventions as found in the @code{strverscmp}
+function.  In fact, if @var{s1} and @var{s2} contain no digits,
+@code{strverscmp} behaves like @code{strcmp}.
+
+Basically, we compare strings normally (character by character), until
+we find a digit in each string - then we enter a special comparison
+mode, where each sequence of digits is taken as a whole.  If we reach the
+end of these two parts without noticing a difference, we return to the
+standard comparison mode.  There are two types of numeric parts:
+"integral" and "fractional" (those  begin with a '0'). The types
+of the numeric parts affect the way we sort them:
+
+@itemize @bullet
+@item
+integral/integral: we compare values as you would expect.
+
+@item
+fractional/integral: the fractional part is less than the integral one.
+Again, no surprise.
+
+@item
+fractional/fractional: the things become a bit more complex.
+If the common prefix contains only leading zeroes, the longest part is less
+than the other one; else the comparison behaves normally.
+@end itemize
+
+@smallexample
+strverscmp ("no digit", "no digit")
+    @result{} 0    // @r{same behavior as strcmp.}
+strverscmp ("item#99", "item#100")
+    @result{} <0   // @r{same prefix, but 99 < 100.}
+strverscmp ("alpha1", "alpha001")
+    @result{} >0   // @r{fractional part inferior to integral one.}
+strverscmp ("part1_f012", "part1_f01")
+    @result{} >0   // @r{two fractional parts.}
+strverscmp ("foo.009", "foo.0")
+    @result{} <0   // @r{idem, but with leading zeroes only.}
+@end smallexample
+
+This function is especially useful when dealing with filename sorting,
+because filenames frequently hold indices/version numbers.
+@end deftypefun
+
+*/
+
+/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
+           fractional parts, S_Z: idem but with leading Zeroes only */
+#define  S_N    0x0
+#define  S_I    0x4
+#define  S_F    0x8
+#define  S_Z    0xC
+
+/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
+#define  CMP    2
+#define  LEN    3
+
+
+/* Compare S1 and S2 as strings holding indices/version numbers,
+   returning less than, equal to or greater than zero if S1 is less than,
+   equal to or greater than S2 (for more info, see the Glibc texinfo doc).  */
+
+int
+strverscmp (const char *s1, const char *s2)
+{
+  const unsigned char *p1 = (const unsigned char *) s1;
+  const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+  int state;
+  int diff;
+
+  /* Symbol(s)    0       [1-9]   others  (padding)
+     Transition   (10) 0  (01) d  (00) x  (11) -   */
+  static const unsigned int next_state[] =
+    {
+      /* state    x    d    0    - */
+      /* S_N */  S_N, S_I, S_Z, S_N,
+      /* S_I */  S_N, S_I, S_I, S_I,
+      /* S_F */  S_N, S_F, S_F, S_F,
+      /* S_Z */  S_N, S_F, S_Z, S_Z
+    };
+
+  static const int result_type[] =
+    {
+      /* state   x/x  x/d  x/0  x/-  d/x  d/d  d/0  d/-
+                 0/x  0/d  0/0  0/-  -/x  -/d  -/0  -/- */
+
+      /* S_N */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_I */  CMP, -1,  -1,  CMP, +1,  LEN, LEN, CMP,
+                 +1,  LEN, LEN, CMP, CMP, CMP, CMP, CMP,
+      /* S_F */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_Z */  CMP, +1,  +1,  CMP, -1,  CMP, CMP, CMP,
+                 -1,  CMP, CMP, CMP
+    };
+
+  if (p1 == p2)
+    return 0;
+
+  c1 = *p1++;
+  c2 = *p2++;
+  /* Hint: '0' is a digit too.  */
+  state = S_N | ((c1 == '0') + (isdigit (c1) != 0));
+
+  while ((diff = c1 - c2) == 0 && c1 != '\0')
+    {
+      state = next_state[state];
+      c1 = *p1++;
+      c2 = *p2++;
+      state |= (c1 == '0') + (isdigit (c1) != 0);
+    }
+
+  state = result_type[state << 2 | (((c2 == '0') + (isdigit (c2) != 0)))];
+
+  switch (state)
+    {
+    case CMP:
+      return diff;
+      
+    case LEN:
+      while (isdigit (*p1++))
+	if (!isdigit (*p2++))
+	  return 1;
+      
+      return isdigit (*p2) ? -1 : diff;
+      
+    default:
+      return state;
+    }
+}

lib/test_process.c

@@ -21,7 +21,9 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <signal.h>
+#ifndef __CYGWIN__
 #include <sys/prctl.h>
+#endif
 #include "c.h"
 
 #define DEFAULT_SLEEPTIME 300
@@ -78,8 +80,10 @@ int main(int argc, char *argv[])
     sigaction(SIGUSR1, &signal_action, NULL);
     sigaction(SIGUSR2, &signal_action, NULL);
 
+#ifndef __CYGWIN__
     /* set process name */
     prctl(PR_SET_NAME, MY_NAME, NULL, NULL, NULL);
+#endif
 
     while (sleep_time > 0) {
 	sleep_time = sleep(sleep_time);

w.c

@@ -182,6 +182,7 @@ static void print_from(const utmp_t *restrict const u, const int ip_addresses, c
 	char buf[fromlen + 1];
 	char buf_ipv6[INET6_ADDRSTRLEN];
 	int len;
+#ifndef __CYGWIN__
 	int32_t ut_addr_v6[4];      /* IP address of the remote host */
 
 	if (ip_addresses) { /* -i switch used */
@@ -219,6 +220,9 @@ static void print_from(const utmp_t *restrict const u, const int ip_addresses, c
 	} else {  /* -i switch NOT used */
 		print_host(u->ut_host, UT_HOSTSIZE, fromlen);
 	}
+#else
+	print_host(u->ut_host, UT_HOSTSIZE, fromlen);
+#endif
 }