### Example: Establish TCP Connection Between Two Zsh Instances (Host 1 - Listener)

Source: https://manpages.ubuntu.com/manpages/stonking/man1/zshmodules.1.html

Demonstrates setting up a TCP connection. This snippet shows the listener setup on host1, including loading the module, starting a listener, and accepting an incoming connection.

```zsh
zmodload zsh/net/tcp
ztcp -l 5123
listenfd=$REPLY
ztcp -a $listenfd
fd=$REPLY
```

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

### Example: RPM installation script for radvd

Source: https://manpages.ubuntu.com/manpages/stonking/man8/systemd-sysusers.service.8.html

This example demonstrates how to use the --replace option to create a user and group during an RPM installation. The configuration is provided directly on the command line, simulating the presence of a configuration file.

```bash
echo 'u radvd - "radvd daemon"' | \
          systemd-sysusers --replace=/usr/lib/sysusers.d/radvd.conf -
```

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

### xsm default startup applications example

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

A sample startup file for xsm, listing applications to be started when a session begins. Each line should contain a command to start an application.

```shell
twm
smproxy
xterm
```

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

### Basic Loop Device Setup and Usage Example

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

This example demonstrates the typical workflow for setting up a loop device: creating an image file, associating it with a loop device, formatting it, mounting it, and finally 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
```

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

### Start a trial session

Source: https://manpages.ubuntu.com/manpages/stonking/man1/tpm2_startauthsession.1.html

This example demonstrates how to start a trial session and save the session data to a file named 'mysession.ctx'.

```APIDOC
## Start a trial session

### Description
Starts a trial authorization session with the TPM and saves the session context to a file.

### Command
tpm2_startauthsession

### Parameters
#### Command Options
- **-S** (string) - Required - Path to save the session context file.

### Example
```bash
tpm2_startauthsession -S mysession.ctx
```
```

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

### Example environment.d configuration file

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

This example shows how to set environment variables for a program installed in /opt/foo, including PATH, LD_LIBRARY_PATH, and XDG_DATA_DIRS. It demonstrates variable expansion and default value assignment.

```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: Loading a provider and getting build information

Source: https://manpages.ubuntu.com/manpages/stonking/man3/OSSL_PROVIDER_get0_name.3.html

This example demonstrates how to load a provider module named 'foo' and then retrieve its build information using OSSL_PROVIDER_get_params.

```APIDOC
## Example: Loading a provider and getting build information

### Description
This example shows how to load the provider module "foo" and query for its build information.

### Code
```c
 #include <openssl/params.h>
 #include <openssl/provider.h>
 #include <openssl/err.h>

 OSSL_PROVIDER *prov = NULL;
 const char *build = NULL;
 OSSL_PARAM request[] = {
     { "buildinfo", OSSL_PARAM_UTF8_PTR, &build, 0, 0 },
     { NULL, 0, NULL, 0, 0 }
 };

 if ((prov = OSSL_PROVIDER_load(NULL, "foo")) != NULL
     && OSSL_PROVIDER_get_params(prov, request))
     printf("Provider 'foo' buildinfo: %s\n", build);
 else
     ERR_print_errors_fp(stderr);
```

### Usage
This code snippet requires including the necessary OpenSSL headers and links against the OpenSSL library. It first attempts to load the provider named "foo". If successful, it then uses `OSSL_PROVIDER_get_params` with a request parameter for "buildinfo" to retrieve the build information string. Errors are printed to stderr.
```

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

### Basic warnquota.conf Example

Source: https://manpages.ubuntu.com/manpages/stonking/man5/warnquota.conf.5.html

A simple configuration example showing FROM, SUPPORT, and PHONE settings. Lines starting with '#' are comments and are ignored.

```shell
# comment
FROM = root@example.com
SUPPORT = support@example.com
PHONE = 1234
```

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

### Starting and Managing a Kernel Process (bufdaemon)

Source: https://manpages.ubuntu.com/manpages/stonking/man9/kproc.9freebsd.html

This example demonstrates how to define a kernel process descriptor and start it using kproc_start. It also shows how to register a shutdown event handler and periodically check for suspension.

```c
static struct proc *bufdaemonproc;

static struct kproc_desc buf_kp = {
	"bufdaemon",
	buf_daemon,
	&bufdaemonproc
};
SYSINIT(bufdaemon, SI_SUB_KTHREAD_BUF, SI_ORDER_FIRST, kproc_start,
    &buf_kp)

static void
buf_daemon()
{
	...
	/*
	 * This process needs to be suspended prior to shutdown sync.
	 */
	EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown,
	    bufdaemonproc, SHUTDOWN_PRI_LAST);
	...
	for (;;) {
		kproc_suspend_check(bufdaemonproc);
		...
	}
}
```

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

### Oneshot Startup Container Example

Source: https://manpages.ubuntu.com/manpages/stonking/man5/podman-systemd.unit.5.html

Defines a oneshot container that runs a setup script before the main application starts. It remains active after exiting.

```ini
[Service]
Type=oneshot
RemainAfterExit=yes
[Container]
Pod=test.pod
Image=quay.io/centos/centos:latest
Exec=sh -c "echo 'setup starting'; sleep 2; echo 'setup complete'"

```

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

### Starting a Transaction Block

Source: https://manpages.ubuntu.com/manpages/stonking/man7/BEGIN.7.html

A simple example demonstrating how to initiate a transaction block using the BEGIN command.

```sql
BEGIN;
```

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

### Read WMI status information

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

This example shows how to read the WMI status device to get information about GUIDs found in the system. The output displays GUIDs along with their instance, expected method, method, string, event, and OID.

```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-A0E0-7045CB4DA745}   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
```

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

### Creating and Mounting a Filesystem

Source: https://manpages.ubuntu.com/manpages/stonking/man2/fsmount.2.html

This example demonstrates opening a filesystem, configuring it, creating a mount object with specific attributes, performing operations on a file within the mount, and finally attaching the mount object to a directory.

```c
int fsfd, mntfd, tmpfd;
fsfd = fsopen("tmpfs", FSOPEN_CLOEXEC);
fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
mntfd = fsmount(fsfd, FSMOUNT_CLOEXEC,
                MOUNT_ATTR_NODEV | MOUNT_ATTR_NOEXEC);
/* Create a new file without attaching the mount object */
tmpfd = openat(mntfd, "tmpfile", O_CREAT | O_EXCL | O_RDWR, 0600);
unlinkat(mntfd, "tmpfile", 0);
/* Attach the mount object to "/tmp" */
move_mount(mntfd, "", AT_FDCWD, "/tmp", MOVE_MOUNT_F_EMPTY_PATH);


```

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

### Xsetup Script Example

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

A sample Xsetup script to configure the environment before the login window appears. It runs as root, so exercise caution with security.

```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 &

```

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

### Compiling and running the key_instantiate example

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

This snippet shows the shell commands to compile the C example program, replace the standard request-key program with the example, run the example to request a key, and then restore the original request-key program.

```bash
$ 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: Start git bisect for performance regression

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

An example of starting a git bisect session with custom terms 'fast' and 'slow' to find a performance regression.

```bash
git bisect start --term-old fast --term-new slow
```

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

### pmrep.conf Example Configuration

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

This example demonstrates setting global options, defining metrics in both compact and verbose forms, and configuring metricsets for different data sources. It shows how to specify metric formulas, widths, and source hosts.

```ini
[options]
timestamp = yes
interval = 2s
extheader = yes
repeat_header = auto
space_scale = MB
[global]
kernel.all.sysfork = forks,,,,8
cacheall = mem.util.allcache
cacheall.formula = mem.util.bufmem + mem.util.cached + mem.util.slab
cacheall.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
```

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

### RUN --network=none Example

Source: https://manpages.ubuntu.com/manpages/stonking/man5/Containerfile.5.html

This example demonstrates isolating external effects by running a pip install command with no network access. This ensures that only provided packages are installed.

```Containerfile
FROM python:3.6
ADD mypackage.tgz wheels/
RUN --network=none pip install --find-links wheels mypackage
```

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

### Using a Pre-configured Options File

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

Demonstrates how a pre-configured options file can simplify keytool commands by providing default options. The example shows how options from the file are merged with command-line arguments.

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

```bash
keytool -conf preconfig -list
```

```bash
keytool -keystore ~/ks -v -list
```

```bash
keytool -conf preconfig -genkeypair -alias me
```

```bash
keytool -keystore ~/ks -keyalg rsa -genkeypair -alias me
```

```bash
keytool -conf preconfig -genkeypair -alias you -keyalg ec
```

```bash
keytool -keystore ~/ks -keyalg rsa -genkeypair -alias you -keyalg ec
```

```bash
keytool -keystore ~/ks -genkeypair -alias you -keyalg ec
```

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

### Example: Start git bisect for bug fix

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

An example of starting a git bisect session with custom terms 'fixed' and 'broken' to find the commit that fixed a bug.

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

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

### Start a service

Source: https://manpages.ubuntu.com/manpages/stonking/man8/initctl.8.html

The 'start' command initiates a service by its name, with an optional ID. Example: 'initctl start tty:1'.

```bash
initctl start NAME[:ID]
```

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

### Initialize Discovery Module and Setup

Source: https://manpages.ubuntu.com/manpages/stonking/man3/pmDiscoverSetup.3.html

Initialize the discovery module with an event loop, configuration, and metric registry, then set up the discovery process with the module, callbacks, and private data. Ensure all declared callbacks are implemented.

```c
pmDiscoverSetEventLoop(&someapp_discover.module, myevents);
pmDiscoverSetConfiguration(&someapp_discover.module, myconfig);
pmDiscoverSetMetricRegistry(&someapp_discover.module, metric_registry);
pmDiscoverSetup(&someapp_discover.module, &someapp_discover.callbacks, &privatedata);

```

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

### Get Session Start Time

Source: https://manpages.ubuntu.com/manpages/stonking/man3/sd_session_get_class.3.html

Retrieve the start time of a systemd session in microseconds.

```c
int sd_session_get_start_time(const char ***_session_**, uint64_t ***_usec_**);
```

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

### Install a Package from an Archive

Source: https://manpages.ubuntu.com/manpages/stonking/man1/dpkg.1.html

Install a package from a .deb archive file. This example shows installing a specific version of vim from a media disc.

```bash
dpkg -i /media/bdrom/pool/main/v/vim/vim_9.0.2018-1_amd64.deb
```

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

### io_uring Setup and Initialization Example

Source: https://manpages.ubuntu.com/manpages/stonking/man7/io_uring.7.html

This C code demonstrates how to set up and initialize an io_uring ring for asynchronous I/O operations. It includes system call wrappers and memory mapping for submission and completion queues.

```c
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
#include <sys/mman.h>
#include <sys/uio.h>
#include <linux/fs.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdatomic.h>
#include <errno.h>
#include <linux/io_uring.h>
#define QUEUE_DEPTH 1
#define BLOCK_SZ    1024
/* Macros for barriers needed by io_uring */
#define io_uring_smp_store_release(p, v)            \
    atomic_store_explicit((_Atomic typeof(*(p)) *)(p), (v), \
                  memory_order_release)
#define io_uring_smp_load_acquire(p)                \
    atomic_load_explicit((_Atomic typeof(*(p)) *)(p),   \
                 memory_order_acquire)
int ring_fd;
unsigned *sring_tail, *sring_mask, *sring_array, 
            *cring_head, *cring_tail, *cring_mask;
struct io_uring_sqe *sqes;
struct io_uring_cqe *cqes;
char buff[BLOCK_SZ];
off_t offset;
/*
 * System call wrappers provided since glibc does not yet
 * provide wrappers for io_uring system calls.
* */
int io_uring_setup(unsigned entries, struct io_uring_params *p)
{
    int ret;
    ret = syscall(__NR_io_uring_setup, entries, p);
    return (ret < 0) ? -errno : ret;
}
int io_uring_enter(int ring_fd, unsigned int to_submit,
                   unsigned int min_complete, unsigned int flags)
{
    int ret;
    ret = syscall(__NR_io_uring_enter, ring_fd, to_submit,
                  min_complete, flags, NULL, 0);
    return (ret < 0) ? -errno : ret;
}
int app_setup_uring(void) {
    struct io_uring_params p;
    void *sq_ptr, *cq_ptr;
    /* See io_uring_setup(2) for io_uring_params.flags you can set */
    memset(&p, 0, sizeof(p));
    ring_fd = io_uring_setup(QUEUE_DEPTH, &p);
    if (ring_fd < 0) {
        perror("io_uring_setup");
        return 1;
    }
    /*
     * io_uring communication happens via 2 shared kernel-user space ring
     * buffers, which can be jointly mapped with a single mmap() call in
     * kernels >= 5.4.
     */
    int sring_sz = p.sq_off.array + p.sq_entries * sizeof(unsigned);
    int cring_sz = p.cq_off.cqes + p.cq_entries * sizeof(struct io_uring_cqe);
    /* Rather than check for kernel version, the recommended way is to
     * check the features field of the io_uring_params structure, which is a 
     * bitmask. If IORING_FEAT_SINGLE_MMAP is set, we can do away with the
     * second mmap() call to map in the completion ring separately.
     */
    if (p.features & IORING_FEAT_SINGLE_MMAP) {
        if (cring_sz > sring_sz)
            sring_sz = cring_sz;
        cring_sz = sring_sz;
    }
    /* Map in the submission and completion queue ring buffers.
     *  Kernels < 5.4 only map in the submission queue, though.
     */
    sq_ptr = mmap(0, sring_sz, PROT_READ | PROT_WRITE, 
                  MAP_SHARED | MAP_POPULATE,
                  ring_fd, IORING_OFF_SQ_RING);
    if (sq_ptr == MAP_FAILED) {
        perror("mmap");
        return 1;
    }
    if (p.features & IORING_FEAT_SINGLE_MMAP) {
        cq_ptr = sq_ptr;
    } else {
        /* Map in the completion queue ring buffer in older kernels separately */
        cq_ptr = mmap(0, cring_sz, PROT_READ | PROT_WRITE,
                      MAP_SHARED | MAP_POPULATE,
                      ring_fd, IORING_OFF_CQ_RING);
        if (cq_ptr == MAP_FAILED) {
            perror("mmap");
            return 1;
        }
    }
    /* Save useful fields for later easy reference */
    sring_tail = sq_ptr + p.sq_off.tail;
    sring_mask = sq_ptr + p.sq_off.ring_mask;
    sring_array = sq_ptr + p.sq_off.array;
    /* Map in the submission queue entries array */
    sqes = mmap(0, p.sq_entries * sizeof(struct io_uring_sqe),
                   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
                   ring_fd, IORING_OFF_SQES);
    if (sqes == MAP_FAILED) {
        perror("mmap");
        return 1;
    }
    /* Save useful fields for later easy reference */
    cring_head = cq_ptr + p.cq_off.head;
    cring_tail = cq_ptr + p.cq_off.tail;
    cring_mask = cq_ptr + p.cq_off.ring_mask;
    cqes = cq_ptr + p.cq_off.cqes;
    return 0;
}
/*
* Read from completion queue.
* In this function, we read completion events from the completion queue.
* We dequeue the CQE, update and head and return the result of the operation.
* */
int read_from_cq() {
    struct io_uring_cqe *cqe;
    unsigned head;
    /* Read barrier */

```

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

### Get installed libcurl version

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

Displays the version information of the currently installed libcurl library.

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

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

### sysctl.conf Example Configurations

Source: https://manpages.ubuntu.com/manpages/stonking/man5/sysctl.conf.5.html

Illustrates how to set kernel parameters, including a domain name and a value containing spaces.

```shell
#
#
kernel.domainname = example.com
; A value containing a space is written to the sysctl.
kernel.modprobe = /sbin/mod probe

```

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

### Getting Maximum Buffer Size

Source: https://manpages.ubuntu.com/manpages/stonking/man3/getgrgid.3.html

Example of how to get the maximum suggested buffer size for reentrant functions.

```c
sysconf(_SC_GETGR_R_SIZE_MAX)
```

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

### Setting up a D-Bus connection and publishing an interface

Source: https://manpages.ubuntu.com/manpages/stonking/man3/sd_bus_set_watch_bind.3.html

This example demonstrates initializing a new bus object, configuring it to wait for D-Bus, setting its address, and publishing an interface. It also shows how to request a well-known name and set up a signal handler for disconnections. The bus is then attached to an event loop.

```c
r = sd_bus_new(o->bus);
  if (r < 0)
    return log_error(r, "sd_bus_new ()");
  r = sd_bus_set_address(*o->bus, "unix:path=/run/dbus/system_bus_socket");
  if (r < 0)
    return log_error(r, "sd_bus_set_address ()");
  r = sd_bus_set_bus_client(*o->bus, 1);
  if (r < 0)
    return log_error(r, "sd_bus_set_bus_client ()");
  r = sd_bus_negotiate_creds(*o->bus, 1, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS);
  if (r < 0)
    return log_error(r, "sd_bus_negotiate_creds ()");
  r = sd_bus_set_watch_bind(*o->bus, 1);
  if (r < 0)
    return log_error(r, "sd_bus_set_watch_bind ()");
  r = sd_bus_start(*o->bus);
  if (r < 0)
    return log_error(r, "sd_bus_start ()");
  /* Publish an interface on the bus, specifying our well-known object access
   * path and public interface name.
   * https://www.freedesktop.org/software/systemd/man/sd_bus_add_object.html
   * https://dbus.freedesktop.org/doc/dbus-tutorial.html
   */
  r = sd_bus_add_object_vtable(*o->bus,
                               NULL,
                               "/org/freedesktop/ReconnectExample",
                               "org.freedesktop.ReconnectExample",
                               vtable,
                               o);
  if (r < 0)
    return log_error(r, "sd_bus_add_object_vtable ()");
  /* By default, the service is only assigned an ephemeral name. Also add a
   * well-known one, so that clients know whom to call. This needs to be
   * asynchronous, as D-Bus might not be yet available. The callback will check
   * whether the error is expected or not, in case it fails.
   * https://www.freedesktop.org/software/systemd/man/sd_bus_request_name.html
   */
  r = sd_bus_request_name_async(*o->bus,
                                NULL,
                                "org.freedesktop.ReconnectExample",
                                0,
                                request_name_callback,
                                o);
  if (r < 0)
    return log_error(r, "sd_bus_request_name_async ()");
  /* When D-Bus is disconnected this callback will be invoked, which will set up
   * the connection again. This needs to be asynchronous, as D-Bus might not yet
   * be available.
   * https://www.freedesktop.org/software/systemd/man/sd_bus_match_signal_async.html
   */
  r = sd_bus_match_signal_async(*o->bus,
                                NULL,
                                "org.freedesktop.DBus.Local",
                                NULL,
                                "org.freedesktop.DBus.Local",
                                "Disconnected",
                                on_disconnect,
                                NULL,
                                o);
  if (r < 0)
    return log_error(r, "sd_bus_match_signal_async ()");
  /* Attach the bus object to the event loop so that calls and signals are
   * processed.
   * https://www.freedesktop.org/software/systemd/man/sd_bus_attach_event.html
   */
  r = sd_bus_attach_event(*o->bus, *o->event, 0);
  if (r < 0)
    return log_error(r, "sd_bus_attach_event ()");
  return 0;
}
```

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

### Get String Length with tmux Formats

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

Expands to the length of the variable. Example gets the length of 'window_name'.

```tmux
#{n:window_name}
```

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

### Live Image Boot Examples

Source: https://manpages.ubuntu.com/manpages/stonking/man7/dracut.cmdline.7.html

Specify the location of your squashed root filesystem for live booting using either a block device or a URL.

```bash
root=live:_< path to blockdevice>_
```

```bash
root=live:_< URL>_
```

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

### FSCONFIG_CMD_CREATE Example

Source: https://manpages.ubuntu.com/manpages/stonking/man2/fsconfig.2.html

Use FSCONFIG_CMD_CREATE to instruct the filesystem driver to instantiate a filesystem instance. _key_ and _value_ must be NULL, and _aux_ must be 0. Requires CAP_SYS_ADMIN capability.

```c
fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
```

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

### rsync --info examples

Source: https://manpages.ubuntu.com/manpages/stonking/man1/rsync.1.html

Examples demonstrating the use of the --info option for controlling output levels. Use --info=help to see all available flags.

```bash
rsync -a --info=progress2 src/ dest/
```

```bash
rsync -avv --info=stats2,misc1,flist0 src/ dest/
```

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

### Add Eshell to Load Path (Example)

Source: https://manpages.ubuntu.com/manpages/stonking/eshell/eshell.texi.html

Example of adding the Eshell installation directory to your load path in .emacs.

```Emacs Lisp
(add-to-list 'load-path "/usr/local/share/emacs/site-lisp/eshell")
```

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

### newhelp Input Syntax Example

Source: https://manpages.ubuntu.com/manpages/stonking/man1/newhelp.1.html

This example demonstrates the basic input syntax for newhelp, showing how to define a performance metric and its description.

```text
#
# This is an example of newhelp's input syntax
#
@ kernel.all.cpu.idle CPU idle time
A cumulative count of the number of milliseconds
of CPU idle time, summed over all processors.

```

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

### Start a policy session

Source: https://manpages.ubuntu.com/manpages/stonking/man1/tpm2_startauthsession.1.html

This example shows how to start a policy session and save the session data to a file named 'mysession.ctx'.

```APIDOC
## Start a policy session

### Description
Starts a policy authorization session with the TPM and saves the session context to a file.

### Command
tpm2_startauthsession

### Parameters
#### Command Options
- **--policy-session** - Optional - Specifies that this is a policy session.
- **-S** (string) - Required - Path to save the session context file.

### Example
```bash
tpm2_startauthsession --policy-session -S mysession.ctx
```
```

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

### Start Xdummy with startx

Source: https://manpages.ubuntu.com/manpages/stonking/man8/Xdummy.8.html

This example shows how to launch Xdummy with display number 2 and a color depth of 16 using startx.

```bash
startx -e bash -- Xdummy :2 -depth 16
```

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

### List available service configurations

Source: https://manpages.ubuntu.com/manpages/stonking/man8/initctl.8.html

Use 'initctl ls' or 'initctl list' to display all *.conf files present in the /etc/finit.d directory.

```bash
initctl ls
```

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

### Get String Width with tmux Formats

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

Expands to the width of the variable when displayed. Example gets the display width of 'window_name'.

```tmux
#{w:window_name}
```

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

### Example Chains and Bindings

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Illustrates rotate, modify, horizontal, key chains, and their resulting bindings based on the example character description table.

```text
Rotate chains: (1w,2w)-1e-1n @r{and} 3w-(2e,3e)-2n. Modify chains: 1w-2w-3w @r{and} 1e-2w-3w and 1n-2n. Horizontal chains: 1e-1w-2e-3e @r{(for modify context @samp{a})}   
2w-3w @r{(for modify context @samp{b})} Key chains: 1e-1w-2e-3e @r{(for context @samp{a})}   
1e-2w-2e-3w @r{(for context @samp{b})}   
1n-1w-2n @r{(for context @samp{c})}   
1n @r{(for context @samp{d})} 
```

```text
Rotate-to: 1w->1e, 2w->1e, 1e->1n, 1n->1w   
3w->2e, 2e->2n, 3e->2n, 2n->3w Modify-to: 1e->1w, 1w->2e, 2e->3e, 3e->1e @r{(horizontal chain)}   
2w->3w, 3w->2w @r{(horizontal chain)}   
1n->2n, 2n->1n @r{(modify chain with exclusive modify contexts)} CONTEXTS: `a'->1e, `b'->1e, `c'->1n, `d'->1n KEY: `a1'=1e, `a2'=1w, `a3'=2e, `a4'=3e, `b1'=1e, ..., `d'=1n
```

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

### Example GRUB Configuration with Serial Console

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

A complete example of a /boot/grub2/grub.cfg file configured for serial console logging.

```grub
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
```

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

### Get Session Start Time

Source: https://manpages.ubuntu.com/manpages/stonking/man3/sd_session_get_desktop.3.html

Retrieve the session's start time in microseconds since the epoch using sd_session_get_start_time.

```c
int sd_session_get_start_time(const char **_session_, uint64_t *_usec_);
```

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

### X-Symbol Installer Address and Package URL

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Defines variables for the X-Symbol installer's email address and the package's URL, used for system-wide installation and package web access.

```texinfo
@vtable @code @item x-symbol-installer-address E-mail address of the person who has installed package X-Symbol system-wide (@pxref{System-wide Installation}).
@item x-symbol-package-url URL of package X-Symbol, used by @code{x-symbol-package-web}. @end vtable
```

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

### Start Image Editor Command

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Starts the image editor and prompts for the image file to edit.

```Emacs Lisp
M-x x-symbol-image-editor
```

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

### Displaying Convert Command Help

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Show help for the 'convert' command, used to check ImageMagick installation.

```Shell
convert -h
```

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

### Buildah Storage Options Example

Source: https://manpages.ubuntu.com/manpages/stonking/man1/buildah.1.html

Demonstrates how to specify storage driver options for Buildah.

```bash
--storage-opt value
```

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

### Start a named screen window

Source: https://manpages.ubuntu.com/manpages/stonking/man1/screen.1.html

Use this command in .screenrc to start a specific command in a named window. This example starts 'nice top' in window 2 and names it 'top'.

```shell
screen -t top 2 nice top
```

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

### Basic .containerignore Example

Source: https://manpages.ubuntu.com/manpages/stonking/man5/containerignore.5.html

This example demonstrates basic pattern matching for excluding files and directories. Lines starting with '#' are comments and are ignored.

```ignore
# comment
*/temp*
*/*/temp*
temp?

```

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

### Example of using cap_new_launcher and cap_launch

Source: https://manpages.ubuntu.com/manpages/stonking/man3/cap_launch.3.html

This example demonstrates creating a launcher for an external command, setting a shared memory detail pointer, invoking the launcher, and then cleaning up the memory. Ensure the detail pointer is correctly managed for inter-process communication.

```c
const char *args[] = { "echo", "hello", NULL };
   cap_launch_t cmd = cap_new_launcher("/usr/bin/echo", args, NULL);
   int *detail = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE,
                      MAP_SHARED | MAP_ANONYMOUS, -1, 0);
   cap_launcher_callback(cmd, &answer_detail_fn);
   *detail = 41;
   pid_t pid = cap_launch(cmd, detail);
   printf("launcher callback set detail to %d\n", *detail);
   munmap(detail, sizeof(int));


```

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

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

Source: https://manpages.ubuntu.com/manpages/stonking/man8/nss-mymachines.8.html

This example shows how to correctly configure the /etc/nsswitch.conf file to enable nss-mymachines. It is recommended to place 'mymachines' before 'resolve' or 'dns' to ensure its mappings are preferred.

```shell
passwd:         files systemd
group:          files [SUCCESS=merge] systemd
shadow:         files 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
```

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

### Get Dirname of Variable with tmux Formats

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

Returns the dirname (directory path) of a path-like variable. Example gets the dirname of 'some/path/variable'.

```tmux
#{d:some/path/variable}
```

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

### Complete AFS File Read Example

Source: https://manpages.ubuntu.com/manpages/stonking/man3/AFS%3A%3Aukernel.3.html

A complete example demonstrating setup, argument parsing, running the AFS kernel module, opening a file, reading its content, closing the file, and shutting down the AFS environment. Error handling is included using die.

```perl
use strict;
use AFS::ukernel;
use POSIX;
my $path = "/afs/localcell/user/adeason/afile";
my $str;
my $code;
my $fd;
$code = AFS::ukernel::uafs_Setup("/afs");
$code == 0 or die("uafs_Setup: $!\n");
$code = AFS::ukernel::uafs_ParseArgs("-afsdb -cachedir /tmp/mycache");
$code == 0 or die("uafs_ParseArgs: $!\n");
$code = AFS::ukernel::uafs_Run();
$code == 0 or due("uafs_Run: $!\n");
$fd = AFS::ukernel::uafs_open($path, POSIX::O_RDONLY);
$fd >=0 or die("uafs_open: $fname: $!\n");
($code, $str) = AFS::ukernel::uafs_read($fd, 4096);
$code >= 0 or die("uafs_read: $!\n");
$code = AFS::ukernel::uafs_close($fd);
$code == 0 or die("uafs_close: $!\n");
print "The first 4096 bytes of $path are:\n$str\n";
AFS::ukernel::uafs_Shutdown();
```

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

### Get Basename of Variable with tmux Formats

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

Returns the basename (last component) of a path-like variable. Example gets the basename of 'some/path/variable'.

```tmux
#{b:some/path/variable}
```

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

### Example Character Description Table

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

An example table illustrating character scores, aspects, and contexts.

```text
An example: Modify Modify Rotate Rotate Modify Other   
Score Aspect Score Aspect Context Contexts -------------------------------------------------------------- charsym 1w 150 nil 100 west `a' `c' charsym 2w 200 nil 100 west `b' - charsym 3w 350 big 100 west (`b') (-) charsym 1e 100 nil 200 east (`a') (`b') charsym 2e 250 big 200 east `a' `b' charsym 3e 300 big 200 east `a' - charsym 1n 100 nil 300 north `d' `c' charsym 2n 200 big 300 north `c' -
```

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

### Initialize X-Symbol in Emacs

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Add this line to your ~/.emacs file to initialize X-Symbol during Emacs startup. Ensure ImageMagick is installed for full image support.

```emacs-lisp
(x-symbol-initialize)
```

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

### Run Minimal Emacs Configuration

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Command to run Emacs with a specific Lisp file, used to test X-Symbol installations and isolate problems.

```Shell
xemacs -no-site-file -q -l @var{my-problem}.el
```

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

### Logging Begin and End of Processing Example

Source: https://manpages.ubuntu.com/manpages/stonking/man7/initramfs-tools.7.html

Provides an example of using log_begin_msg and log_end_msg to bracket a block of processing, indicating its start and completion.

```sh
log_begin_msg "Frobnication begun"
# Do something
log_end_msg
```

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

### io_setup()

Source: https://manpages.ubuntu.com/manpages/stonking/man3/io_setup.3.html

Creates an asynchronous I/O context for processing a specified number of operations concurrently.

```APIDOC
## io_setup()

### Description
Creates an asynchronous I/O context suitable for concurrently processing _n_ operations.

### Library
Asynchronous I/O library (_libaio_, _-laio_)

### Synopsis
```c
#include <libaio.h>
long io_setup(unsigned int *_n_, io_context_t ***_ctx_idp_);
```

### Return Value
On success, **io_setup**() returns 0. On error, a negative error code is returned to indicate the error.

### Errors
See **io_setup**(2).

### Standards
libaio.

### History
libaio.
```

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

### Load Kernel and Initfs with Command Line

Source: https://manpages.ubuntu.com/manpages/stonking/man1/0xFFFF.1.html

Load a kernel and initfs, then boot the device with a specified command line via USB.

```bash
$ 0xFFFF -m initfs:<file> -m kernel:<file> -l -b "<cmdline>"
```

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

### Start an encrypted and bound policy session

Source: https://manpages.ubuntu.com/manpages/stonking/man1/tpm2_startauthsession.1.html

This example demonstrates starting an encrypted and bound policy session, requiring a primary context file.

```APIDOC
## Start an encrypted and bound policy session

### Description
Starts an encrypted and bound policy authorization session with the TPM, using a primary context, and saves the session context to a file.

### Command
tpm2_startauthsession

### Parameters
#### Command Options
- **--policy-session** - Optional - Specifies that this is a policy session.
- **-c** (string) - Required - Path to the primary context file.
- **-S** (string) - Required - Path to save the session context file.

### Example
```bash
tpm2_createprimary -c primary.ctx
tpm2_startauthsession --policy-session -c primary.ctx -S mysession.ctx
```
```

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

### Check Message Log in Emacs

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Type 'M-x show-message-log' to check for any problems or errors that occurred during file loading after installation.

```emacs-lisp
M-x show-message-log
```

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

### nfacct accounting data example

Source: https://manpages.ubuntu.com/manpages/stonking/man8/iptables-extensions.8.html

Example output from 'nfacct get http-traffic', showing the packet and byte counts for the 'http-traffic' accounting object.

```json
{ "pkts" = 00000000000000000156, "bytes" = 00000000000000151786 } = http-traffic;
```

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

### Displaying Images in HTML

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

This example demonstrates the HTML img tag format recognized by X-Symbol for displaying images. The '@var{ext}' placeholder represents image file extensions like gif, png, or jpeg.

```HTML
<img @var{@dots{}} src="@var{file}.@var{ext}" @var{@dots{}}>
```

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

### Example Character Definition

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

An example of defining a character with its score and associated symbols in a character table.

```lisp
(aacute 225 (acute "a" Aacute))
```

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

### Example cdrskin Startup File Content

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

Demonstrates the format of a cdrskin startup file, including device selection and other options. Lines starting with '#' are comments, and empty lines are ignored.

```shell
# This is the default device
dev=0,1,0
# Some more options
fifo_start_at=0
fs=16m
```

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

### Multihead Configuration Example

Source: https://manpages.ubuntu.com/manpages/stonking/man4/glide.4.html

An example xorg.conf snippet demonstrating a multihead setup with the fbdev driver for the first monitor and the glide driver for the second.

```xorg.conf
**Section "Monitor"**  
**  Identifier "Monitor 1"**  
**  VendorName "Unknown"**  
**  ModelName "Unknown"**  
**  HorizSync 30-70**  
**  VertRefresh 50-80**  

```

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

### Example of checking thin provisioning metadata

Source: https://manpages.ubuntu.com/manpages/stonking/man8/thin_check.8.html

This example demonstrates how to analyze the thin provisioning metadata on a logical volume. Ensure the device is not actively used by the thin target during this operation.

```bash
$ thin_check /dev/vg/metadata

```

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

### Start gpg-agent for SSH Agent

Source: https://manpages.ubuntu.com/manpages/stonking/man1/gpg-agent.1.html

Use this command to start the gpg-agent specifically for its Secure Shell Agent functionality. No additional setup is required.

```bash
gpg-connect-agent /bye
```

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

### Querying Locale for Character Encoding

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

This example demonstrates how to query the system's locale settings to determine the character encoding. This information is used by X-Symbol to identify the normal file encoding, especially in environments without Mule support.

```Shell
locale -ck code_set_name charmap
```

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

### Show a service configuration

Source: https://manpages.ubuntu.com/manpages/stonking/man8/initctl.8.html

Use 'initctl show' to display the content of a specified .conf file in /etc/finit.d/available.

```bash
initctl show CONF
```

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

### Getting Server Info in ZenIRC

Source: https://manpages.ubuntu.com/manpages/stonking/zenirc/zenirc.texi.html

Use the /info command to get various details about a server, including version, compile date, and start time.

```irc
/info [server]
```

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

### Get capture file start and end times

Source: https://manpages.ubuntu.com/manpages/stonking/man1/mergecap.1.html

Use capinfos to determine the start and end times of capture files, which are necessary for time adjustments.

```bash
capinfos -aeS a.pcap b.pcap
```

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

### D-Bus Connection and Event Loop Setup in C

Source: https://manpages.ubuntu.com/manpages/stonking/man8/systemd-soft-reboot.service.8.html

This example demonstrates setting up a D-Bus connection and an event loop in C using systemd libraries. It includes signal handling for graceful termination and asynchronous D-Bus signal matching. Ensure proper initialization and cleanup of D-Bus and event loop resources.

```c
int main(int argc, char **argv) {
  /* The bus should be relinquished before the program terminates. The cleanup
   * attribute allows us to do it nicely and cleanly whenever we exit the block.
   */
  _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
  _cleanup_(sd_event_unrefp) sd_event *event = NULL;
  object o = {
    .example = "example",
    .bus = &bus,
    .event = &event,
  };
  int r;
  /* Create an event loop data structure, with default parameters.
   * https://www.freedesktop.org/software/systemd/man/sd_event_default.html
   */
  r = sd_event_default(&event);
  if (r < 0)
    return log_error(r, "sd_event_default()") ;
  /* By default, the event loop will terminate when all sources have disappeared,
   * so we have to keep it 'occupied'. Register signal handling to do so.
   * https://www.freedesktop.org/software/systemd/man/sd_event_add_signal.html
   */
  r = sd_event_add_signal(event, NULL, SIGINT|SD_EVENT_SIGNAL_PROCMASK, NULL, NULL);
  if (r < 0)
    return log_error(r, "sd_event_add_signal(SIGINT)");
  r = sd_event_add_signal(event, NULL, SIGTERM|SD_EVENT_SIGNAL_PROCMASK, NULL, NULL);
  if (r < 0)
    return log_error(r, "sd_event_add_signal(SIGTERM)");
  r = setup(&o);
  if (r < 0)
    return EXIT_FAILURE;
  /* Enter the main loop, it will exit only on sigint/sigterm.
   * https://www.freedesktop.org/software/systemd/man/sd_event_loop.html
   */
  r = sd_event_loop(event);
  if (r < 0)
    return log_error(r, "sd_event_loop()") ;
  /* https://www.freedesktop.org/software/systemd/man/sd_bus_release_name.html */
  r = sd_bus_release_name(bus, "org.freedesktop.ReconnectExample");
  if (r < 0)
    return log_error(r, "sd_bus_release_name()") ;
  return 0;
}
```

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

### Start a container instance with sudo

Source: https://manpages.ubuntu.com/manpages/stonking/man8/runc-spec.8.html

Use this command when the runc process requires root privileges to start a container instance. Ensure you have sudo installed and configured.

```bash
sudo runc start container1
```

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

### Finit Templating Example

Source: https://manpages.ubuntu.com/manpages/stonking/man5/finit.conf.5.html

Demonstrates how to use Finit's templating feature, similar to systemd, to instantiate services with dynamic parameters. Use '%i' as a placeholder for the instance name.

```bash
$ initctl show avahi-autoipd@
service :%i avahi-autoipd --syslog %i -- ZeroConf for %i
```

```bash
$ initctl enable avahi-autoipd@eth0.conf
```

```bash
$ initctl status avahi-autoipd:eth0
```

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

### Start Image Editor with Mouse Button 2

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Initiates the image editor for a highlighted image using the second mouse button. If the image is in the search path, it edits the existing file; otherwise, it opens a new file in the first search path directory.

```Emacs Lisp
@key{button2}
```

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

### iptables conntrack example: Match related connections

Source: https://manpages.ubuntu.com/manpages/stonking/man8/iptables-extensions.8.html

This example matches packets that are starting a new connection but are associated with an existing one, such as FTP data transfers.

```bash
iptables -m conntrack --ctstate RELATED
```

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

### Example Input Definition for aacute

Source: https://manpages.ubuntu.com/manpages/stonking/x-symbol/x-symbol.texi.html

Defines the 'aacute' character with specific contexts and modifications to its score. It uses the 'acute' group and 'a' subgroup, with defined input sequences.

```lisp
(acute 0 "%s'" t "'%s")
```

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

### iptables conntrack example: Match new connections

Source: https://manpages.ubuntu.com/manpages/stonking/man8/iptables-extensions.8.html

This example matches packets that are starting a new connection or are associated with a connection that has not yet seen packets in both directions.

```bash
iptables -m conntrack --ctstate NEW
```