libprocps version test and documentation

test binary and man page for the version part of libprocps.
It's a simple start, but it's a start!

Makefile.am

@@ -53,7 +53,8 @@ dist_man_MANS = \
 	uptime.1 \
 	vmstat.8 \
 	w.1 \
-	ps/ps.1
+	ps/ps.1 \
+	doc/procps_linux_version.3
 
 EXTRA_DIST = \
 	.version \
@@ -248,10 +249,7 @@ check_PROGRAMS = \
 	lib/test_strutils \
 	lib/test_fileutils \
 	lib/test_process \
-	proc/test_sysinfo \
+	$(TESTS)
-	proc/test_namespace \
-	lib/test_process \
-	lib/test_strtod_nol
 
 lib_test_strutils_SOURCES = lib/test_strutils.c lib/strutils.c
 lib_test_strutils_LDADD = $(CYGWINFLAGS)
@@ -266,6 +264,8 @@ 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
+proc_test_version_SOURCES = include/tests.h proc/test_version.c
+proc_test_version_LDADD = proc/libprocps.la
 lib_test_strtod_nol_SOURCES = lib/test_strtod_nol.c lib/strutils.c
 lib_test_strtod_nol_LDADD = $(CYGWINFLAGS)
 
@@ -277,6 +277,7 @@ BUILT_SOURCES = $(top_srcdir)/.version
 
 TESTS = proc/test_sysinfo \
 	proc/test_namespace \
+	proc/test_version \
 	lib/test_strtod_nol
 
 $(top_srcdir)/.version:

doc/procps_linux_version.3

@@ -0,0 +1,63 @@
+.\"
+.\" (C) Copyright 2016 Craig Small <csmall@enc.com.au>
+.\"
+.TH PROCPS_LINUX_VERSION 3 2016-04-14
+.\" Please adjust this date whenever revising the manpage.
+.\"
+.SH NAME
+procps_linux_version \-
+provide current version of Linux as an integer
+.SH SYNOPSIS
+.B #include <proc/procps.h>
+.sp
+.B int procps_linux_version(void);
+.sp
+Link with \fI\-lprocps\fP.
+.SH DESCRIPTION
+The function
+.BR procps_linux_version ()
+returns the current Linux version as an integer. On systems that have an emulated proc filesystem this function returns the
+version of the Linux emulation instead.
+
+The Linux version consists of a triple of positive integers representing the major, minor and patch versions of the kernel. 
+The library provides 3 macros for separating out the components.
+.RS 4
+.TP 1.2i
+.BR LINUX_VERSION_MAJOR (ver)
+Extract the major component from the given version integer.
+.TP
+.BR LINUX_VERSION_MINOR (ver)
+Extract the minor component from the given version integer.
+.TP
+.BR LINUX_VERSION_PATCH (ver)
+Extract the patch component from the given version integer.
+.RE
+.PP
+To encode a given Linux version, such as using it to compare against the current 
+version, use the following macro:
+.TP
+.BI LINUX_VERSION( major , minor , patch )
+
+.SH RETURN VALUE
+On success,
+.BR procps_linux_version ()
+return a positive integer which is the encoded Linux kernel version;
+on error, it returns a negative integer.
+
+.SH ERRORS
+On error, 
+.BR procps_linux_version ()
+may return the following values as errors:
+.TP
+.B -EIO
+The procps library was unable to read the osrelease file.
+.TP
+.B -ERANGE
+Unable to parse the osrelease file.
+.PP
+.BR procps_linux_version ()
+may also return any (negated) value that \fBfopen\fR() may return.
+
+.SH SEE ALSO
+.BR fopen (3),
+.BR proc (5).

include/tests.h

@@ -0,0 +1,10 @@
+
+#ifndef PROCPS_NG_TESTS_H
+#define PROCPS_NG_TESTS_H
+
+struct test_func {
+    int (*func)(void *data);
+    char *name;
+};
+
+#endif

proc/.gitignore

@@ -1,2 +1,3 @@
-test_sysinfo
 test_namespace
+test_version
+test_sysinfo

proc/test_version.c

@@ -0,0 +1,54 @@
+/*
+ * libprocps - Library to read proc filesystem
+ * Tests for version library calls
+ *
+ * Copyright 2016 Craig Small <csmall@enc.com.au>
+ *
+ * This library 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.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <proc/version.h>
+#include "tests.h"
+
+int check_linux_version(void *data)
+{
+    return (procps_linux_version() > 0);
+}
+
+struct test_func tests[] = {
+    { check_linux_version, "procps_linux_version()"},
+    { NULL, NULL}
+};
+
+int main(int argc, char *argv[])
+{
+    int i;
+    struct test_func *current;
+
+    for(i=0; tests[i].func != NULL; i++) {
+        current = &tests[i];
+        if (!current->func(NULL)) {
+            fprintf(stderr, "FAIL: %s\n", current->name);
+            return EXIT_FAILURE;
+        } else {
+            fprintf(stderr, "PASS: %s\n", current->name);
+        }
+    }
+    return EXIT_SUCCESS;
+}
+
+