Ubuntu Manpages Jammy

https://manpages.ubuntu.com/manpages/jammy/
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### Example Environment Variable Setup

Source: https://manpages.ubuntu.com/manpages/jammy/man5/environment.d.5.html

Sets environment variables to allow access to a program installed in /opt/foo. Demonstrates basic assignment, PATH modification, and referencing existing variables with fallbacks.

```shell
        FOO_DEBUG=force-software-gl,log-verbose
        PATH=/opt/foo/bin:$PATH
        LD_LIBRARY_PATH=/opt/foo/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
        XDG_DATA_DIRS=/opt/foo/share:${XDG_DATA_DIRS:-/usr/local/share/:/usr/share/}
        
```

--------------------------------

### Example Project Configuration File

Source: https://manpages.ubuntu.com/manpages/jammy/man1/man1/worklog.1.html

This is an example of a project configuration file for worklog. Each line defines a project key and its name, with comments starting with '#'.

```shell
# Worklog project file
# note that projects appear in Worklog in REVERSE order
B:BOWER consultation
L:LIS consultation
R:Research
D:DEC system administration
P:Problems email
S:Sugar administration
r:Reading NetNews

```

--------------------------------

### Example Configuration for virtio-net Module

Source: https://manpages.ubuntu.com/manpages/jammy/man5/modules-load.d.5.html

This example shows a configuration file for loading the 'virtio-net' kernel module at boot. Empty lines and lines starting with '#' or ';' are ignored.

```shell
# Load virtio-net.ko at boot
virtio-net
```

--------------------------------

### Display WMI status information

Source: https://manpages.ubuntu.com/manpages/jammy/man4/acpi_wmi.4freebsd.html

Read the WMI status device to get information about GUIDs found in the system. This output shows example data.

```shell
# cat /dev/wmistat0
GUID                                  INST EXPE METH STR EVENT OID
{5FB7F034-2C63-45E9-BE91-3D44E2C707E4}   1 NO   WMAA NO  NO    AA
{95F24279-4D7B-4334-9387-ACCDC67EF61C}   1 NO   NO   NO  0x80+ -
{2B814318-4BE8-4707-9D84-A190A859B5D0}   1 NO   NO   NO  0xA0  -
{05901221-D566-11D1-B2F0-00A0C9062910}   1 NO   NO   NO  NO    AB
{1F4C91EB-DC5C-460B-951D-C7CB9B4B8D5E}   1 NO   WMBA NO  NO    BA
{2D114B49-2DFB-4130-B8FE-4A3C09E75133}  57 NO   NO   NO  NO    BC
{988D08E3-68F4-4C35-AF3E-6A1B8106F83C}  20 NO   NO   NO  NO    BD
{14EA9746-CE1F-4098-0AE0-7045CB4DA745}   1 NO   NO   NO  NO    BE
{322F2028-0F84-4901-988E-015176049E2D}   2 NO   NO   NO  NO    BF
{8232DE3D-663D-4327-A8F4-E293ADB9BF05}   0 NO   NO   NO  NO    BG
{8F1F6436-9F42-42C8-BADC-0E9424F20C9A}   0 NO   NO   NO  NO    BH
{8F1F6435-9F42-42C8-BADC-0E9424F20C9A}   0 NO   NO   NO  NO    BI
```

--------------------------------

### Basic Loop Device Setup and Usage

Source: https://manpages.ubuntu.com/manpages/jammy/man8/losetup.8.html

This example demonstrates the common workflow of creating a file, setting it up as a loop device, formatting it, mounting it, and then unmounting and detaching it.

```bash
# dd if=/dev/zero of=~/file.img bs=1024k count=10
# losetup --find --show ~/file.img
/dev/loop0
# mkfs -t ext2 /dev/loop0
# mount /dev/loop0 /mnt
...
# umount /dev/loop0
# losetup --detach /dev/loop0
```

--------------------------------

### Initial Mount Points Setup

Source: https://manpages.ubuntu.com/manpages/jammy/man7/mount_namespaces.7.html

Sets up the initial mount points on the system before demonstrating the 'unbindable' mount example. This involves listing existing mounts.

```bash
# **mount | awk '{print $1, $2, $3}'**
/dev/sda1 on /
/dev/sdb6 on /mntX
/dev/sdb7 on /mntY
```

--------------------------------

### Default Startup Applications Example

Source: https://manpages.ubuntu.com/manpages/jammy/man1/xsm.1.html

A sample startup file for xsm, listing applications to be launched when a session begins.

```bash
twm
smproxy
xterm
```

--------------------------------

### Perl Module Installation Example

Source: https://manpages.ubuntu.com/manpages/jammy/skk/skk-faq.texi.html

Example of installing a Perl module from CPAN for SKK customization.

```Perl
CPAN modules/by-category/Development_Support/Make-1.00.tar.gz
```

--------------------------------

### Example Usage of pktsetup

Source: https://manpages.ubuntu.com/manpages/jammy/man8/pktsetup.8.html

Demonstrates the typical workflow for setting up a packet device, mounting it, and then tearing down the association.

```bash
cdrwtool -d /dev/sr0 -q
pktsetup 0 /dev/sr0
mount -t udf /dev/pktcdvd0 /mnt
...
umount /dev/pktcdvd0
pktsetup -d 0
```

--------------------------------

### Start SystemTap server for all installed kernels

Source: https://manpages.ubuntu.com/manpages/jammy/man8/stap-server.8.html

This command starts the SystemTap compile server and configures it to handle all kernel versions installed in the /lib/modules directory.

```bash
[ service ] stap-server start -i
```

--------------------------------

### Configuration File Example 2

Source: https://manpages.ubuntu.com/manpages/jammy/man1/curl.1.html

Shows how to specify multiple URLs and referer headers within a configuration file.

```bash
# and fetch another URL too
 url = "example.com/docs/manpage.html"
 -O
 referer = "http://nowhereatall.example.com/"
# --- End of example file ---
```

--------------------------------

### Get Language Example

Source: https://manpages.ubuntu.com/manpages/jammy/MANUAL.ps.html

This snippet shows how to get the language.

```PostScript
get language (e
```

--------------------------------

### Xsetup Script Example

Source: https://manpages.ubuntu.com/manpages/jammy/man1/xdm.1.html

A sample shell script for the Xsetup file, which runs after the server is reset but before the login window is offered. It includes commands to configure X color management and start a console window.

```shell
	#!/bin/sh
	# Xsetup_0 - setup script for one workstation
	xcmsdb < /etc/X11/xdm/monitors/alex.0
	xconsole	-geometry	480x130-0-0	-notify	-verbose	-exitOnFail &

```

--------------------------------

### NFS mount pivot_root example

Source: https://manpages.ubuntu.com/manpages/jammy/man8/pivot_root.8.html

This example demonstrates mounting a new root over NFS and then using pivot_root to switch to it. It includes necessary setup like configuring the loopback interface, starting portmap, mounting the NFS share, and then executing init within the new root context. It also shows how to handle potential issues like portmap keeping the old root busy.

```bash
ifconfig lo 127.0.0.1 up   # for portmap
# configure Ethernet or such
portmap   # for lockd (implicitly started by mount)
mount -o ro 10.0.0.1:/my_root /mnt
killall portmap   # portmap keeps old root busy
cd /mnt
pivot_root . old_root
exec chroot . sh -c 'umount /old_root; exec /sbin/init' \
  <dev/console >dev/console 2>&1
```

--------------------------------

### Option Syntax Examples

Source: https://manpages.ubuntu.com/manpages/jammy/man5/xorg.conf.d.5.html

Illustrates equivalent ways to set or negate options using the 'Option' keyword. Useful for understanding flexible configuration settings.

```xorg.conf
Option "Accel"   "Off"
Option "NoAccel"
```

```xorg.conf
Option "NoAccel" "On"
Option "Accel"   "false"
```

```xorg.conf
Option "Accel"   "no"
```

--------------------------------

### SKK Undo Kanji Conversion Example

Source: https://manpages.ubuntu.com/manpages/jammy/skk/skk.texi.html

Example of undoing a Kanji conversion in SKK. It shows inputting '333' and then pressing SPC to get '亜', and then pressing SPC again to get 'あ'.

```emacs-lisp
@example ?$B$3$&$3$&?(B /?$B9b9;?(B/?$B9'9T?(B/?$B9R9T?(B/ @end example
```

--------------------------------

### Get installed libcurl version

Source: https://manpages.ubuntu.com/manpages/jammy/man1/curl-config.1.html

This command displays the version information of the currently installed libcurl.

```bash
curl-config --version
```

--------------------------------

### Example usage of get_nprocs_conf and get_nprocs

Source: https://manpages.ubuntu.com/manpages/jammy/man3/get_nprocs_conf.3.html

This C code example demonstrates how to use `get_nprocs_conf()` to get the number of configured processors and `get_nprocs()` to get the number of available processors, printing the results to standard output.

```c
#include <stdlib.h>
#include <stdio.h>
#include <sys/sysinfo.h>

int
main(int argc, char *argv[])
{
    printf("This system has %d processors configured and "
            "%d processors available.\n",
            get_nprocs_conf(), get_nprocs());
    exit(EXIT_SUCCESS);
}

```

--------------------------------

### execle Example

Source: https://manpages.ubuntu.com/manpages/jammy/man3/execvp.3.html

Shows how to use execle to replace the current process and specify a custom environment for the new process. Arguments are passed as a list.

```c
int execle(const char *pathname, const char *arg, ... /*, (char *) NULL, char *const envp[] */);
```

--------------------------------

### Example .pc file structure

Source: https://manpages.ubuntu.com/manpages/jammy/man5/pc.5.html

Demonstrates the basic structure of a .pc file, including comments, variable definitions, and various properties like Name, Version, Libs, and Cflags.

```pkgconfig
# This is a comment
prefix=/home/kaniini/pkg   # this defines a variable
exec_prefix=${prefix}      # defining another variable with a substitution
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Name: libfoo                                  # human-readable name
Description: an example library called libfoo # human-readable description
Version: 1.0
URL: http://www.pkgconf.org
Requires: libbar > 2.0.0
Conflicts: libbaz <= 3.0.0
Libs: -L${libdir} -lfoo
Libs.private: -lm
Cflags: -I${includedir}/libfoo
```

--------------------------------

### Install a custom SELinux module

Source: https://manpages.ubuntu.com/manpages/jammy/man8/semanage-module.8.html

Use this command to install a custom SELinux policy module. The example shows installing a module named 'myapache'.

```bash
# semanage module -a myapache
```

--------------------------------

### Pre-configured Options File Example

Source: https://manpages.ubuntu.com/manpages/jammy/man1/keytool.1.html

An example of a pre-configured options file for keytool, demonstrating how to set default options for all commands ('keytool.all') and specific commands ('keytool.list', 'keytool.genkeypair').

```properties
# A tiny pre-configured options file
keytool.all = -keystore ${user.home}/ks
keytool.list = -v
keytool.genkeypair = -keyalg rsa
```

--------------------------------

### Tmux String Truncation from Start Example

Source: https://manpages.ubuntu.com/manpages/jammy/man1/tmux.1.html

Limits the pane title to a maximum of 5 characters from the start.

```tmux
#{=5:pane_title}
```

--------------------------------

### Get Resource Start Address

Source: https://manpages.ubuntu.com/manpages/jammy/man9/rman.9.html

Retrieves the starting address of a resource. Requires a valid resource structure.

```c
#include <sys/types.h>
#include <sys/rman.h>
rman_res_t rman_get_start(struct resource *r);
```

--------------------------------

### Setting up play directories for symlinks example

Source: https://manpages.ubuntu.com/manpages/jammy/man1/tcsh.1.html

This snippet demonstrates the setup of directories and a symbolic link for testing the 'symlinks' variable behavior.

```shell
> cd /tmp
> mkdir from from/src to
> ln -s from/src to/dst
```

--------------------------------

### Get Information About an Application

Source: https://manpages.ubuntu.com/manpages/jammy/man1/flatpak-remote-info.1.html

This example shows how to retrieve detailed information about the 'org.gnome.gedit' application from the 'flathub' remote repository using the user installation. The output includes the matched ref, application ID, architecture, branch, build date, commit details, size information, and the associated runtime.

```bash
$ flatpak --user remote-info flathub org.gnome.gedit

```

--------------------------------

### Compile and run key_instantiate example

Source: https://manpages.ubuntu.com/manpages/jammy/man2/keyctl.2.html

This snippet demonstrates how to compile the C example program 'key_instantiate.c' using GCC, link it with '-lkeyutils', and then use it to temporarily replace the system's 'request-key' program to instantiate a key. It also shows how to revert to the original 'request-key' program.

```shell
$ **cc -o key_instantiate key_instantiate.c -lkeyutils**
$ **sudo mv /sbin/request-key /sbin/request-key.backup**
$ **sudo cp key_instantiate /sbin/request-key**
$ **./t_request_key user mykey somepayloaddata**
Key ID is 20d035bf
$ **sudo mv /sbin/request-key.backup /sbin/request-key**

```

--------------------------------

### Example Configuration in files.arch

Source: https://manpages.ubuntu.com/manpages/jammy/man9/firmware.9.html

This example from sys/arm/xscale/ixp425/files.ixp425 shows how to embed firmware images. It requires tools like awk, make, compiler, and linker.

```makefile
ixp425_npe_fw.c                         optional npe_fw                 \
        compile-with    "${AWK} -f $S/tools/fw_stub.awk
			IxNpeMicrocode.dat:npe_fw -mnpe -c${.TARGET}" \
        no-implicit-rule before-depend local                            \
        clean           "ixp425_npe_fw.c"
```

```makefile
IxNpeMicrocode.fwo  optional npe_fw					\
        dependency      "IxNpeMicrocode.dat"					\
        compile-with    "${LD} -b binary -d -warn-common					\
			    -r -d -o ${.TARGET} IxNpeMicrocode.dat"					\
        no-implicit-rule                                                \
        clean           "IxNpeMicrocode.fwo"
```

```makefile
IxNpeMicrocode.dat                      optional npe_fw                 \
        dependency      ".PHONY"							\
        compile-with    "uudecode < $S/contrib/dev/npe/IxNpeMicrocode.dat.uu" \
        no-obj no-implicit-rule                                         \
        clean           "IxNpeMicrocode.dat"
```

--------------------------------

### Run a Container

Source: https://manpages.ubuntu.com/manpages/jammy/man1/docker-run.1.html

Starts a new container in detached mode, interactive, and with a pseudo-TTY. This is a basic example to start a container.

```bash
# docker run --name=link-test -d -i -t fedora/httpd

```

--------------------------------

### List installed rlwrap filters

Source: https://manpages.ubuntu.com/manpages/jammy/man1/rlwrap.1.html

Use the -z option to get a list of all currently installed rlwrap filters.

```bash
rlwrap -z listing
```

--------------------------------

### Create Initial Files

Source: https://manpages.ubuntu.com/manpages/jammy/man7/gitcore-tutorial.7.html

Create two sample files in the working directory to begin tracking with Git.

```bash
$ echo "Hello World" >hello
$ echo "Silly example" >example
```

--------------------------------

### pmrep.conf Example Configuration

Source: https://manpages.ubuntu.com/manpages/jammy/man5/pmrep.conf.5.html

This example demonstrates setting local options, defining global metrics using compact and verbose forms, and configuring metricsets for different data sources. It shows how to specify default reporting values and mimic existing tools.

```config
[options]
timestamp = yes
interval = 2s
extheader = yes
repeat_header = auto
space_scale = MB
[global]
kernel.all.sysfork = forks,,,,8
allcache = mem.util.allcache
allcache.formula = mem.util.bufmem + mem.util.cached + mem.util.slab
allcache.width = 12
[db1]
source = db-host1.example.com
set = postgresql
[db2]
source = db-host2.example.com
set = postgresql
[sar-w]
header = yes
unitinfo = no
globals = no
timestamp = yes
precision = 2
delimiter = " "
kernel.all.sysfork = proc/s,,,,12
kernel.all.pswitch = cswch/s,,,,9
```

--------------------------------

### rpm Command Usage Examples

Source: https://manpages.ubuntu.com/manpages/jammy/man1/busybox.1.html

Manipulates RPM packages. Examples show installing a package and querying package information.

```bash
rpm -i PACKAGE.rpm; rpm -qp[ildc] PACKAGE.rpm
```

--------------------------------

### Implement -x Option Example

Source: https://manpages.ubuntu.com/manpages/jammy/man1/hexdump.1.html

Demonstrates how to implement the functionality of the -x option using format strings.

```shell
   "%07.7_Ax\n"
   "%07.7_ax  " 8/2 "%04x " "\n"
```

--------------------------------

### Filter Locales by Prefix

Source: https://manpages.ubuntu.com/manpages/jammy/man8/zypper.8.html

Retrieves locales that start with a specific language code. The example shows locales starting with 'en'.

```bash
zypper locales en_
```

```bash
zypper locales en *
```

--------------------------------

### Example: Configuring and Verifying Hostnames

Source: https://manpages.ubuntu.com/manpages/jammy/man3/SSL_add1_host.3.html

This example demonstrates setting hostnames for verification, including primary and additional hostnames, and then checking the verification result. It retrieves the matched peername if verification is successful.

```c
SSL_set_hostflags(ssl, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS);
if (!SSL_set1_host(ssl, "smtp.example.com"))
    /* error */
if (!SSL_add1_host(ssl, "example.com"))
    /* error */
/* XXX: Perform SSL_connect() handshake and handle errors here */
if (SSL_get_verify_result(ssl) == X509_V_OK) {
    const char *peername = SSL_get0_peername(ssl);
    if (peername != NULL)
        /* Name checks were in scope and matched the peername */
}

```

--------------------------------

### Example: Skip 'doc*' Directory

Source: https://manpages.ubuntu.com/manpages/jammy/man1/git-svn.1.html

An example of using the --ignore-paths option to skip any path starting with 'doc' during fetches.

```shell
--ignore-paths="^doc"
```

--------------------------------

### Extracting an afio archive from a specific track

Source: https://manpages.ubuntu.com/manpages/jammy/man1/cdrskin.1.html

This example demonstrates how to retrieve an afio archive from a specific track on a CD. It uses cdrskin to get the table of contents, then processes the output with grep, tail, and awk to find the track's starting LBA. Finally, it uses dd to extract the data and pipes it to afio.

```bash
tracknumber=2
lba=$(cdrskin dev=/dev/cdrom -toc 2>&1 | \
grep '^track:[ ]*[ 0-9][0-9]' | \
tail +"$tracknumber" | head -1 | \
awk '{ print $4}')
dd if=/dev/cdrom bs=2048 skip="$lba" | \
afi o -t - | less
```

--------------------------------

### Example: setq for generating 'fortran'

Source: https://manpages.ubuntu.com/manpages/jammy/MANUAL.ps.html

Demonstrates the use of 'setq' to generate 'fortran'. This is a basic example of variable assignment and generation.

```ps
<1>: (setq *gentran 'fortran)
```

--------------------------------

### Start Process Accounting

Source: https://manpages.ubuntu.com/manpages/jammy/man5/acct.5.html

Example of how to start process accounting by calling the acct(2) system call with the path to the accounting file.

```c
#include <sys/acct.h>

acct("/var/log/pacct");

```

--------------------------------

### Example /etc/nsswitch.conf configuration for nss-resolve

Source: https://manpages.ubuntu.com/manpages/jammy/man8/nss-resolve.8.html

This example demonstrates the recommended configuration for /etc/nsswitch.conf to enable nss-resolve. It shows the correct ordering of 'mymachines', 'resolve', 'files', 'myhostname', and 'dns' for host lookups.

```shell
passwd:         compat systemd
group:          compat [SUCCESS=merge] systemd
shadow:         compat systemd
gshadow:        files systemd
hosts:          mymachines **resolve [!UNAVAIL=return]** files myhostname dns
networks:       files
protocols:      db files
services:       db files
ethers:         db files
rpc:            db files
netgroup:       nis
```

--------------------------------

### Example: setq for generating 'c'

Source: https://manpages.ubuntu.com/manpages/jammy/MANUAL.ps.html

Demonstrates using 'setq' to generate 'c'. This is a specific use case for generating C code.

```ps
<1>: (setq *gentran 'c)
```

--------------------------------

### Interactive Program Notice Example

Source: https://manpages.ubuntu.com/manpages/jammy/man7/gpl.7.html

Example of a notice to display when an interactive program starts, informing users about its warranty status and redistribution conditions.

```text
Gnomovision version 69, Copyright (C) <year> <name of author>
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
```

--------------------------------

### Example usage of thin_rmap with a region

Source: https://manpages.ubuntu.com/manpages/jammy/man8/thin_rmap.8.html

An example of how to run the thin_rmap command to get the reverse map for a specific region of blocks on a metadata device.

```bash
$ **thin_rmap** **--region** 5..45 /dev/pool-metadata
```

--------------------------------

### Interactive Ethernet Connection Setup

Source: https://manpages.ubuntu.com/manpages/jammy/man7/nmcli-examples.7.html

This example demonstrates an interactive session for creating an Ethernet connection profile with static IP addressing and DNS configuration.

```bash
nmcli> verify
Verify connection: OK
nmcli> save
Connection 'ethernet-4' (de89cdeb-a3e1-4d53-8fa0-c22546c775f4) successfully
 saved.
nmcli> quit
```

--------------------------------

### Install and Initialize Prompt Themes

Source: https://manpages.ubuntu.com/manpages/jammy/man1/zshcontrib.1.html

Add custom prompt theme functions to fpath, autoload promptinit, and initialize the prompt system. Assumes functions are in ~/myfns.

```zsh
fpath=(~/myfns $fpath)
autoload -U promptinit
promptinit
```

--------------------------------

### Example Flatpak Installation Configuration

Source: https://manpages.ubuntu.com/manpages/jammy/man5/flatpak-installation.5.html

Defines an additional system-wide flatpak installation named 'extra' located at /location/of/sdcard, intended for use with an SD card.

```ini
[Installation "extra"]
Path=/location/of/sdcard
DisplayName=Extra Installation
StorageType=sdcard

```

--------------------------------

### Conjunctive Flow Setup Example

Source: https://manpages.ubuntu.com/manpages/jammy/man7/ovs-fields.7.html

This example demonstrates setting up a conjunctive flow using the 'conjunction' action. It includes flows for matching IP source and destination, and a final flow matching the conjunctive ID.

```openflow
conj_id=1234 actions=controller
ip,ip_src=10.0.0.1 actions=conjunction(1234, 1/2)
ip,ip_src=10.0.0.4 actions=conjunction(1234, 1/2)
ip,ip_src=10.0.0.6 actions=conjunction(1234, 1/2)
ip,ip_src=10.0.0.7 actions=conjunction(1234, 1/2)
ip,ip_dst=10.0.0.2 actions=conjunction(1234, 2/2)
ip,ip_dst=10.0.0.5 actions=conjunction(1234, 2/2)
ip,ip_dst=10.0.0.7 actions=conjunction(1234, 2/2)
ip,ip_dst=10.0.0.8 actions=conjunction(1234, 2/2)
```

--------------------------------

### dracut --fscks example

Source: https://manpages.ubuntu.com/manpages/jammy/man8/dracut.8.html

Example of adding a list of fsck tools to the initramfs. The installation is opportunistic. Enclose multiple tool names in quotes.

```bash
# dracut --fscks "fsck1 fsck2"  ...
```

--------------------------------

### Example: Starting a New Cookie Session with libcurl

Source: https://manpages.ubuntu.com/manpages/jammy/man3/CURLOPT_COOKIESESSION.3.html

Demonstrates how to use CURLOPT_COOKIESESSION to start a new cookie session and load non-session cookies from a file.

```c
CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
  /* new "session", do not load session cookies */
  curl_easy_setopt(curl, CURLOPT_COOKIESESSION, 1L);
  /* get the (non session) cookies from this file */
  curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "/tmp/cookies.txt");
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}
```

--------------------------------

### Example GRUB Configuration with Serial Console

Source: https://manpages.ubuntu.com/manpages/jammy/man8/dracut.8.html

A complete example of a GRUB configuration file including serial console settings and kernel arguments.

```bash
default=0
timeout=5
serial --unit=0 --speed=9600
terminal --timeout=5 serial console
title Fedora (2.6.29.5-191.fc11.x86_64)
  root (hd0,0)
  kernel /vmlinuz-2.6.29.5-191.fc11.x86_64 ro root=/dev/mapper/vg_uc1-lv_root console=tty0 console=ttyS0,9600
  initrd /dracut-2.6.29.5-191.fc11.x86_64.img
```

--------------------------------

### Start pmdatxmon agent

Source: https://manpages.ubuntu.com/manpages/jammy/man1/pmdatxmon.1.html

pmdatxmon is launched by pmcd and should never be executed directly. The Install and Remove scripts notify pmcd when the agent is installed or removed.

```shell
$PCP_PMDAS_DIR/txmon/pmdatxmon [ -d domain ] [ -l logfile ] [ -U username ] _tx_type ...

```

--------------------------------

### Example: Output file list (current-output)

Source: https://manpages.ubuntu.com/manpages/jammy/MANUAL.ps.html

This example demonstrates how to manage the current output file list. It shows the basic structure for specifying output files.

```ps
|current-output|
v
++++++++++++++++++++
|t |
```

--------------------------------

### Example: Starting git bisect for a bug fix

Source: https://manpages.ubuntu.com/manpages/jammy/man1/git-bisect.1.html

Start a bisect session to find the commit that fixed a bug, using 'fixed' and 'broken' as custom terms.

```bash
git bisect start --term-new fixed --term-old broken
```

--------------------------------

### Example: Setting an Executable to Spawn

Source: https://manpages.ubuntu.com/manpages/jammy/man3/sd_bus_set_exec.3.html

Configures a list of addresses for bus brokers to try connecting to. This example specifies an executable path and arguments to spawn.

```c
int ret;
ret = sd_bus_set_address(bus, "unixexec:path=/usr/bin/my-bus-daemon,argv1=--foreground,argv2=--log-level=debug");
```

--------------------------------

### Install SysV init script with default links

Source: https://manpages.ubuntu.com/manpages/jammy/man8/update-rc.d.8.html

Use this command to install a SysV init script with default start and stop dependencies and runlevel configurations.

```bash
update-rc.d foobar defaults
```

--------------------------------

### Key Instantiation Example (C)

Source: https://manpages.ubuntu.com/manpages/jammy/man2/keyctl.2.html

This C code demonstrates how to instantiate a key using the KEYCTL_INSTANTIATE operation. It logs various details about the key and its associated data to a file. Ensure the necessary headers are included and the program is executed with appropriate arguments.

```c
#include <sys/types.h>
#include <keyutils.h>
#include <time.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#ifndef KEY_SPEC_REQUESTOR_KEYRING
#define KEY_SPEC_REQUESTOR_KEYRING      -8
#endif
int
main(int argc, char *argv[])
{
    FILE *fp;
    time_t t;
    char *operation;
    key_serial_t key_to_instantiate, dest_keyring;
    key_serial_t thread_keyring, process_keyring, session_keyring;
    uid_t uid;
    gid_t gid;
    char dbuf[256];
    char auth_key_payload[256];
    int akp_size;       /* Size of auth_key_payload */
    int auth_key;
    fp = fopen("/tmp/key_instantiate.log", "w");
    if (fp == NULL)
        exit(EXIT_FAILURE);
    setbuf(fp, NULL);
    t = time(NULL);
    fprintf(fp, "Time: %s\n", ctime(&t));
    /*
     * The kernel passes a fixed set of arguments to the program
     * that it execs; fetch them.
     */
    operation = argv[1];
    key_to_instantiate = atoi(argv[2]);
    uid = atoi(argv[3]);
    gid = atoi(argv[4]);
    thread_keyring = atoi(argv[5]);
    process_keyring = atoi(argv[6]);
    session_keyring = atoi(argv[7]);
    fprintf(fp, "Command line arguments:\n");
    fprintf(fp, "  argv[0]:            %s\n", argv[0]);
    fprintf(fp, "  operation:          %s\n", operation);
    fprintf(fp, "  key_to_instantiate: %jx\n",
            (uintmax_t) key_to_instantiate);
    fprintf(fp, "  UID:                %jd\n", (intmax_t) uid);
    fprintf(fp, "  GID:                %jd\n", (intmax_t) gid);
    fprintf(fp, "  thread_keyring:     %jx\n",
            (uintmax_t) thread_keyring);
    fprintf(fp, "  process_keyring:    %jx\n",
            (uintmax_t) process_keyring);
    fprintf(fp, "  session_keyring:    %jx\n",
            (uintmax_t) session_keyring);
    fprintf(fp, "\n");
    /*
     * Assume the authority to instantiate the key named in argv[2]
     */
    if (keyctl(KEYCTL_ASSUME_AUTHORITY, key_to_instantiate) == -1) {
        fprintf(fp, "KEYCTL_ASSUME_AUTHORITY failed: %s\n",
                strerror(errno));
        exit(EXIT_FAILURE);
    }
    /*
     * Fetch the description of the key that is to be instantiated
     */
    if (keyctl(KEYCTL_DESCRIBE, key_to_instantiate,
                dbuf, sizeof(dbuf)) == -1) {
        fprintf(fp, "KEYCTL_DESCRIBE failed: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }
    fprintf(fp, "Key description:      %s\n", dbuf);
    /*
     * Fetch the payload of the authorization key, which is
     * actually the callout data given to request_key() 
     */
    akp_size = keyctl(KEYCTL_READ, KEY_SPEC_REQKEY_AUTH_KEY,
                      auth_key_payload, sizeof(auth_key_payload));
    if (akp_size == -1) {
        fprintf(fp, "KEYCTL_READ failed: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }
    auth_key_payload[akp_size] = '\0';
    fprintf(fp, "Auth key payload:     %s\n", auth_key_payload);
    /*
     * For interest, get the ID of the authorization key and
     * display it.
     */
    auth_key = keyctl(KEYCTL_GET_KEYRING_ID,
            KEY_SPEC_REQKEY_AUTH_KEY);
    if (auth_key == -1) {
        fprintf(fp, "KEYCTL_GET_KEYRING_ID failed: %s\n",
                strerror(errno));
        exit(EXIT_FAILURE);
    }
    fprintf(fp, "Auth key ID:          %jx\n", (uintmax_t) auth_key);
    /*
     * Fetch key ID for the request_key(2) destination keyring.
     */
    dest_keyring = keyctl(KEYCTL_GET_KEYRING_ID,
                          KEY_SPEC_REQUESTOR_KEYRING);
    if (dest_keyring == -1) {
        fprintf(fp, "KEYCTL_GET_KEYRING_ID failed: %s\n",
                strerror(errno));
        exit(EXIT_FAILURE);
    }
    fprintf(fp, "Destination keyring:  %jx\n", (uintmax_t) dest_keyring);
    /*
     * Fetch the description of the authorization key. This
     * allows us to see the key type, UID, GID, permissions, 
     * and description (name) of the key. Among other things,
     * we will see that the name of the key is a hexadecimal
     * string representing the ID of the key to be instantiated.
     */
    if (keyctl(KEYCTL_DESCRIBE, KEY_SPEC_REQKEY_AUTH_KEY,
                dbuf, sizeof(dbuf)) == -1) {
        fprintf(fp, "KEYCTL_DESCRIBE failed: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }
    fprintf(fp, "Auth key description: %s\n", dbuf);
    /*
     * Instantiate the key using the callout data that was supplied
     * in the payload of the authorization key.
     */
    if (keyctl(KEYCTL_INSTANTIATE, key_to_instantiate,
               auth_key_payload, akp_size + 1, dest_keyring) == -1) {
        fprintf(fp, "KEYCTL_INSTANTIATE failed: %s\n",
                strerror(errno));
        exit(EXIT_FAILURE);
    }
    exit(EXIT_SUCCESS);
}

```

--------------------------------

### Setting Initial Heap Size

Source: https://manpages.ubuntu.com/manpages/jammy/man1/java.1.html

Examples demonstrating how to set the initial heap size using different units (bytes, kilobytes, megabytes).

```bash
-XX:InitialHeapSize=6291456
```

```bash
-XX:InitialHeapSize=6144k
```

```bash
-XX:InitialHeapSize=6m
```
Tokens:
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