Initial code for a few Unix 'libc' API(s)

CHANGES.md

@@ -23,6 +23,7 @@ Features
 * [#548](https://github.com/java-native-access/jna/pull/548): Return 64-bit unsigned integer from `com.sun.jna.platform.win32.WinBase.FILETIME` - [@dbwiddis](https://github.com/dbwiddis).
 * [#524](https://github.com/java-native-access/jna/pull/524): Added IShellFolder interface plus necessary utility functions to Windows platform, and a sample for enumerating objects in My Computer - [@lwahonen](https://github.com/lwahonen).
 * [#484](https://github.com/twall/jna/pull/484): Added `XFetchName` to `X11` interface - [@pinaf](https://github.com/pinaf).
+* [#554](https://github.com/java-native-access/jna/pull/554): Initial code for a few Unix 'libc' API(s) [@lgoldstein](https://github.com/lgoldstein)
 
 Bug Fixes
 ---------

contrib/platform/src/com/sun/jna/platform/unix/LibC.java

@@ -0,0 +1,25 @@
+/* Copyright (c) 2015 Goldstein Lyor, All Rights Reserved
+ *
+ * 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.
+ */
+package com.sun.jna.platform.unix;
+
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+
+/**
+ * <I>libc</I> API
+ * @author Lyor Goldstein
+ */
+public interface LibC extends LibCAPI, Library {
+    String NAME = "c";
+    LibC INSTANCE = (LibC) Native.loadLibrary(NAME, LibC.class);
+}

contrib/platform/src/com/sun/jna/platform/unix/LibCAPI.java

@@ -0,0 +1,76 @@
+/* Copyright (c) 2015 Goldstein Lyor, All Rights Reserved
+ *
+ * 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.
+ */
+package com.sun.jna.platform.unix;
+
+/**
+ * Note: we are using this "intermediate" API in order to allow
+ * Linux-like O/S-es to implement the same API, but maybe using a different
+ * library name
+ * @author Lyor Goldstein
+ */
+public interface LibCAPI extends Reboot, Resource {
+    // see man(2) get/set uid/gid
+    int getuid();
+    int geteuid();
+    int getgid();
+    int getegid();
+
+    int setuid(int uid);
+    int seteuid(int uid);
+    int setgid(int gid);
+    int setegid(int gid);
+
+    // see man(2) get/set hostname
+    int HOST_NAME_MAX = 255; // not including the '\0'
+    int gethostname(char[] name, int len);
+    int sethostname(char[] name, int len);
+
+    // see man(2) get/set domainname
+    int getdomainname(char[] name, int len);
+    int setdomainname(char[] name, int len);
+
+    /**
+     * @param name Environment variable name
+     * @return Returns the value in the environment, or {@code null} if there
+     * is no match for the name
+     * @see <A HREF="https://www.freebsd.org/cgi/man.cgi?query=setenv&sektion=3">getenv(3)</A>
+     */
+    String getenv(String name);
+
+    /**
+     * Update or add a variable in the environment of the calling process.
+     * @param name Environment variable name
+     * @param value Required value
+     * @param overwrite  If the environment variable already exists and the
+     * value of {@code overwrite} is non-zero, the function shall return
+     * success and the environment shall be updated. If the environment
+     * variable already exists and the value of {@code overwrite} is zero, the
+     * function shall return success and the environment shall remain unchanged.
+     * @return Upon successful completion, zero shall be returned. Otherwise,
+     * -1 shall be returned, {@code errno} set to indicate the error, and the
+     * environment shall be unchanged
+     * @see <A HREF="https://www.freebsd.org/cgi/man.cgi?query=setenv&sektion=3">getenv(3)</A>
+     */
+    int setenv(String name, String value, int overwrite);
+
+    /**
+     * @param name Environment variable name - If the named variable does not
+     * exist in the current environment, the environment shall be unchanged
+     * and the function is considered to have completed successfully.
+     * @return Upon successful completion, zero shall be returned. Otherwise,
+     * -1 shall be returned, {@code errno} set to indicate the error, and the
+     * environment shall be unchanged
+     * @see <A HREF="https://www.freebsd.org/cgi/man.cgi?query=setenv&sektion=3">getenv(3)</A>
+     */
+    int unsetenv(String name);
+}

contrib/platform/src/com/sun/jna/platform/unix/Reboot.java

@@ -0,0 +1,43 @@
+/* Copyright (c) 2015 Goldstein Lyor, All Rights Reserved
+ *
+ * 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.
+ */
+package com.sun.jna.platform.unix;
+
+/**
+ * Contains definitions related to the {@code reboot} API
+ * @author Lyor Goldstein
+ */
+public interface Reboot {
+    /** Perform a hard reset now.  */
+    int RB_AUTOBOOT = 0x01234567;
+    /* Halt the system.  */
+    int RB_HALT_SYSTEM = 0xcdef0123;
+    /** Enable reboot using Ctrl-Alt-Delete keystroke.  */
+    int RB_ENABLE_CAD = 0x89abcdef;
+    /** Disable reboot using Ctrl-Alt-Delete keystroke.  */
+    int RB_DISABLE_CAD = 0;
+    /** Stop system and switch power off if possible.  */
+    int RB_POWER_OFF = 0x4321fedc;
+    /** Suspend system using software suspend.  */
+    int RB_SW_SUSPEND = 0xd000fce2;
+    /** Reboot system into new kernel.  */
+    int RB_KEXEC = 0x45584543;
+
+    /**
+     * Stops/Reboots the machine
+     * @param cmd The command
+     * @return If successful, this call never returns.  Otherwise, a -1
+     * is returned and an error is returned in the global variable {@code errno}.
+     * @see <A HREF="http://www.unix.com/man-page/freebsd/2/reboot/">man 2 reboot</A>
+     */
+    int reboot(int cmd);
+}

contrib/platform/src/com/sun/jna/platform/unix/Resource.java

@@ -0,0 +1,101 @@
+/* Copyright (c) 2015 Goldstein Lyor, All Rights Reserved
+ *
+ * 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.
+ */
+package com.sun.jna.platform.unix;
+
+import java.util.Arrays;
+import java.util.List;
+
+import com.sun.jna.Structure;
+
+/**
+ * Definitions related to {@code getrlimit}/{@code setrlimit}
+ * @author Lyor Goldstein
+ */
+public interface Resource {
+    /** Per-process CPU limit, in seconds.  */
+    int RLIMIT_CPU = 0;
+
+    /** Largest file that can be created, in bytes.  */
+    int RLIMIT_FSIZE = 1;
+
+    /** Maximum size of data segment, in bytes.  */
+    int RLIMIT_DATA = 2;
+
+    /** Maximum size of stack segment, in bytes.  */
+    int RLIMIT_STACK = 3;
+
+    /** Largest core file that can be created, in bytes.  */
+    int RLIMIT_CORE = 4;
+
+    /**
+     * Largest resident set size, in bytes. This affects swapping; processes
+     * that are exceeding their resident set size will be more likely to have
+     * physical memory taken from them.
+     */
+    int RLIMIT_RSS = 5;
+
+    /** Number of open files.  */
+    int RLIMIT_NOFILE = 7;
+
+    /** Address space limit.  */
+    int RLIMIT_AS = 9;
+
+    /** Number of processes.  */
+    int RLIMIT_NPROC = 6;
+
+    /** Locked-in-memory address space.  */
+    int RLIMIT_MEMLOCK = 8;
+
+    /** Maximum number of file locks.  */
+    int RLIMIT_LOCKS = 10;
+
+    /** Maximum number of pending signals.  */
+    int RLIMIT_SIGPENDING = 11;
+
+    /** Maximum bytes in POSIX message queues.  */
+    int RLIMIT_MSGQUEUE = 12;
+
+    /**
+     * Maximum nice priority allowed to raise to. Nice levels 19 .. -20
+     * correspond to 0 .. 39 values of this resource limit.
+     */
+    int RLIMIT_NICE = 13;
+    int RLIMIT_RTPRIO = 14;
+
+    /**
+     * Maximum CPU time in microseconds that a process scheduled under a
+     * real-time scheduling policy may consume without making a blocking
+     * system call before being forcibly de-scheduled.
+     */
+    int RLIMIT_RTTIME = 15;
+
+    /** Number of {@code rlimit} values */
+    int RLIMIT_NLIMITS = 16;
+
+    public static class Rlimit extends Structure {
+        /** The current (soft) limit.  */
+        public long rlim_cur;
+
+        /** The hard limit.  */
+        public long rlim_max;
+
+        @Override
+        protected List<String> getFieldOrder() {
+            return Arrays.asList(new String[] { "rlim_cur", "rlim_max" });
+        }
+    }
+
+    // see man(2) rlimit
+    int getrlimit(int resource, Rlimit rlim);
+    int setrlimit(int resource, Rlimit rlim);
+}