[talks/lbs] Reworked files and directories slides, added some examples for files in /etc

1 files changed, 97 insertions, 65 deletions

diff --git a/src/talks/linuxgraphy-by-strabo/index.md b/src/talks/linuxgraphy-by-strabo/index.md
index 5ef6f99..b944584 100644
--- a/src/talks/linuxgraphy-by-strabo/index.md
+++ b/src/talks/linuxgraphy-by-strabo/index.md
@@ -940,44 +940,41 @@ Most modern shells support a lot of the more defying features of the [Bourne She
 
 
 
-&&slide
+&&clide &&font35
 
 ## 3.2. Files and directories
 
+- `/dev`: devices
+- `/proc`: process information
+
+&&lineb3
+
 - `/bin`: main command programs (binaries), used by users
-- `/etc`: system configuration files
 - `/sbin`: command programs, used for the system operation
 - `/usr`: other system resources
   + `/usr/bin`: all other user command binaries
-  + `/usr/lib`: library files
-  + `/usr/local`: local, system software
-  + `/usr/share`: architecture independent data, like manuals
-- `/var`: variable data, like logs and cache
-- `/dev`: devices
-- `/home`: home directories of all users
-- `/lib`: libraries and kernel modules
-- `/mnt`: mounted temporary filesystems
-- `/proc`: process information
-- `/root`: home directory for the root user
 
-&&/slide
+&&/font &&/clide
 
 
 
 &&slide
 
-### General file system commands
+#### Everyday file system commands
 
 - `mkdir`: create directories
 - `rm`: remove a (hardlink to) file or directory
-- `shred`: overwrite file contents
 - `mv`: move file (or directory) to another directory
 - `cp`: copy a file
 - `ln`: create hard (or soft, with `-s`) links to files (inodes)
 - `ls`: list directory contents
+
+#### Other useful file system commands
+
+- `shred`: overwrite file contents
 - `dd`: do many things with files, like modifying and duplicating data across devices and partitions, (basic) data recovery and generating files
 - `du`: estimate file usage
-- `stat`: display status for file system or file system
+- `stat`: display status for file or file system
 - `chwon`: change owner of an inode
 - `chgrp`: change group of an inode
 - `chmod`: change file modes
@@ -989,17 +986,20 @@ Most modern shells support a lot of the more defying features of the [Bourne She
 
 &&slide
 
-### Working with text (files)
+#### Everyday text (file) commands
 
 - `echo`: prints a given string to standard output
 - `cat`: sequentially prints files to standard output
 - `less`: view files with support for scrolling
-- `grep`: searches for matches in a file, using simplified regular expressions. Often there is `egrep`, which allows for extended regex and `fgrep` where strings are matched as-is.
+- `head`: print the first lines (or characters) of a file
+- `tail`: print the last lines (or characters) of a file
+
+#### Other useful text (file) commands
+
+- `grep`: searches for matches in a file, using simplified regular expressions. `egrep` for extended regex and `fgrep` for string match (as-is).
 - `sed`: filter and transform text from files, according to regex
 - `tr`: translate, map (more than one to one for example) and delete characters
 - `cut`: remove parts of text from each line
-- `head`: print the first lines (or characters) of a file
-- `tail`: print the last lines (or characters) of a file
 - `strings`: find embedded text inside binary files
 - `truncate`: shrink or extend the size of a file
 - `wc`: count words inside file
@@ -1009,87 +1009,119 @@ Most modern shells support a lot of the more defying features of the [Bourne She
 
 
 
-&&slide
+&&clide
 
-### Working with devices
+#### Device commands
 
 - `mount`: bind another file system to a location in the file system
 - `umount`: remove binding to a file system
+- `lsusb`: lists USB devices
+- `lspci`: lists PCI devices
 
-&&/slide
+#### System information commands
 
+- `date`: display current date and time
+- `hostname`: show (or set) the systems hostname (network name)
+- `free`: display free memory on the system
 
+&&/clide
 
-&&slide
 
-## 3.3 Common configuration files
 
-&&lineb1
+&&slide
 
-- `/etc/group`: the data for all groups is stored here, in the format
+#### User and group management
 
-  ```
-  GROUPNAME:PASSWORD:GID:USERS...
-  ```
+- `useradd`: creates a new user (with a password)
+- `userdel`: remove a user and all of his files
+- `usermod`: modify a user account, including his name and groups
+- `passwd`: change password of a user. With `-l` user could be locked (impossible to log in)
 
-- `/etc/passwd`: the data for all users is stored here, in the format
+&&lineb1
 
-  ```
-  USERNAME:PASSWORD:UID:GID:USERINFO:HOMEDIR:SHELL
-  ```
+- `groupadd`: create a new group
+- `groupdel`: remove a group
+- `groupmod`: modify an existing group
 
-- `/etc/shadow`: stores other user data, especially the password as an encrypted string, in the format
+&&lineb1
 
-  ```
-  USERNAME:PASSWORD:LASTCHANGED:MINBETWEENCHANGES:MAXBETWEENCHANGES:WARNEXPIRE:INACTIVEDAYS:EXPIRE
-  ```
+- `w`: show who is logged in and what they are doing
+- `who`: show who is logged in
+- `whomai`: print username
+- `login`: establish a new connection to the system
 
 &&/slide
 
 
 
-&&clide
+&&slide
 
-- `/etc/fstab`: mountings of devices to the file system, read on boot by mount
-- `/etc/hosts`: list of host names (domain names) and their corresponding IP address, when a DNS server doesn't do the job
-- `/etc/bashrc`: global defaults and aliases used by the bash shell
+- `/etc`: system configuration files
+  &&lineb2
 
-&&/clide
+  + `/etc/group`: the data for all groups is stored here, in the format
 
+    ```
+    GROUPNAME:PASSWORD:GID:USERS...
+    ```
 
+  + `/etc/passwd`: the data for all users is stored here, in the format
 
-&&slide
+    ```
+    USERNAME:PASSWORD:UID:GID:USERINFO:HOMEDIR:SHELL
+    ```
 
-## 3.4. System management
+  + `/etc/shadow`: stores other user data, especially the password as an encrypted string, in the format
 
-- System information
-  + `date`: display current date and time
-  + `hostname`: show (or set) the systems hostname (network name)
-  + `free`: display free memory on the system
+    ```
+    USERNAME:PASSWORD:LASTCHANGED:MINBETWEENCHANGES:MAXBETWEENCHANGES:WARNEXPIRE:INACTIVEDAYS:EXPIRE
+    ```
 
 &&/slide
 
 
 
-&&clide
+&&slide &&font27
 
-- Users and groups
-  + `useradd`: creates a new user (with a password)
-  + `userdel`: remove a user and all of his files
-  + `usermod`: modify a user account, including his name and groups
-  + `passwd`: change password of a user. With `-l` user could be locked (impossible to log in)
-  &&lineb1
-  + `groupadd`: create a new group
-  + `groupdel`: remove a group
-  + `groupmod`: modify an existing group
-  &&lineb1
-  + `w`: show who is logged in and what they are doing
-  + `who`: show who is logged in
-  + `whomai`: print username
-  + `login`: establish a new connection to the system
+-  
 
+  + `/etc/fstab`: read on boot by mount to setup devices in fs
 
-&&/clide
+    ```
+    # device-spec   mount-point  fs-type  options              dump  pass
+    /dev/sda1       /            ext4     defaults             1     1
+    UUID=123A-456B  /boot        vfat     noauto,noatime       1     2
+    LABEL=Vault     /mnt/Vault   auto     nosuid,nodev,nofail  0     0
+    ```
+
+  + `/etc/hosts`: list of host names (domain names) and their corresponding IP address, when a DNS server doesn't do the job
+    
+    ```
+    # ipaddress    domains
+    127.0.0.1      localhost mywebsite.com something.else
+    62.44.101.138  my.uni
+    ```
+
+  + `/etc/bashrc`: global defaults and aliases used by the bash shell
+  + `/etc/motd`: message of the day (unexecuted text), shown after login but before the shell is ran
+
+&&/font &&/slide
+
+
+
+&&clide &&font35
+
+- `/usr`: other system resources
+  + `/usr/lib`: library files
+  + `/usr/local`: local, system software
+  + `/usr/share`: architecture independent data, like manuals
+- `/var`: variable data, like logs and cache
+- `/home`: home directories of all users
+- `/lib`: libraries and kernel modules
+- `/mnt`: mounted temporary filesystems
+- `/root`: home directory for the root user
+
+&&/font &&/clide