more updates and formatting updates

Author: gbowne1

regex.md

@@ -5,3 +5,38 @@ I don't know a lot about regex.  I don't assume that many people know about how
 https://regex101.com is your friend.
 
 A lot of Regex tutorials or even makeshift Regex guides kind of miss the mark.
+
+Here are some basics
+
+Matching Characters:
+
+    . (dot): Matches any single character except newline.
+    [a-z]: Matches any lowercase letter.
+    [A-Z]: Matches any uppercase letter.
+    [0-9]: Matches any digit.
+    \w (word character): Matches any alphanumeric character (a-z, A-Z, 0-9, and underscore).
+    \s (whitespace): Matches any whitespace character (space, tab, newline).
+
+Quantifiers:
+
+    *: Matches zero or more of the preceding element.
+    +: Matches one or more of the preceding element.
+    ?: Matches zero or one of the preceding element.
+    {n}: Matches exactly n occurrences of the preceding element.
+    {m,n}: Matches between m and n occurrences of the preceding element.
+
+Anchors:
+
+    ^: Matches the beginning of the string.
+    $: Matches the end of the string.
+
+Grouping:
+
+    (): Groups characters for repeated matching or capturing.
+
+Other Symbols:
+
+    \d: Matches any digit (equivalent to [0-9]).
+    \D: Matches any non-digit (opposite of \d).
+    \b: Matches a word boundary (beginning or end of a word).
+    \: Escapes the special meaning of a following character.

using-apt.md

@@ -3,3 +3,31 @@
 `apt list --upgradable`
 `apt update`
 `apt upgrade`
+`apt install <package_name>`: Installs a specific package.
+`apt remove <package_name>`: Removes a package but keeps configuration files.
+`apt purge <package_name>`: Removes a package and all its configuration files.
+`apt install -f`: Attempts to fix broken dependencies during installation.
+`apt show <package_name>`: Shows detailed information about a package.
+`apt depends <package_name>`: Lists the dependencies of a package.
+`apt search <keyword>`: Searches for packages based on keywords.
+`apt full-upgrade`: Upgrades packages and also removes any outdated packages.
+`apt autoremove`: Removes unused dependencies automatically.
+`apt clean`: Removes all downloaded package files (.deb).
+`apt autoclean`: Removes only outdated downloaded package files, keeping the latest ones.
+`apt edit-sources`: Opens the sources.list file for editing repository configurations.
+`apt-cache policy <package_name>`: Shows the installation state and available versions of a package.
+`apt-cache show <package_name>`: Shows detailed information about a package from the cache.
+`apt-get install <package_name>`: Installs a specific package.
+`apt-get install -f`: Attempts to fix broken dependencies during installation.
+`apt-get install -d <package_name>`: Downloads the package without installing it.
+`apt-get remove <package_name>`: Removes a package but keeps configuration files.
+`apt-get purge <package_name>`: Removes a package and all its configuration files.
+`apt-get upgrad`e: Upgrades all installed packages to the latest versions.
+`apt-get dist-upgrade`: Upgrades packages and also removes any outdated packages.
+`apt-get show <package_name>`: Shows detailed information about a package.
+`apt-get depends <package_name>`: Lists the dependencies of a package.
+`apt-get search <keyword>`: Searches for packages based on keywords.
+`apt-get update`: Updates the package list with the latest information from repositories.
+`apt-get autoremove`: Removes unused dependencies automatically.
+`apt-get clean`: Removes all downloaded package files (.deb).
+`apt-get autoclean`: Removes only outdated downloaded package files, keeping the latest ones.

using-find-command.md

@@ -15,7 +15,7 @@ My version of find comes from /usr/bin/find /usr/share/man/man1/find.1.gz /usr/s
 
 find -a says `find: invalid expression; you have used a binary operator '-a' with nothing before it.`
 
-find -d says `ind: warning: the -d option is deprecated; please use -depth instead, because the latter is a POSIX-compliant feature.`
+find -d says `find: warning: the -d option is deprecated; please use -depth instead, because the latter is a POSIX-compliant feature.`
 
 find -o says `find: invalid expression; you have used a binary operator '-o' with nothing before it.`
 

using-gcc.md

@@ -7,11 +7,13 @@ My gcc is currently in /usr/bin/gcc /usr/lib/gcc and is gcc version 8.3.0 (Debia
 There are some important flags that can be used with GCC to compile C programs.
 these were tested by doing each flag individually. These may or may not be documented.
 
+using GNU g++ (for C++) may use these same flags as gcc.
+
 ### Lowercase flags
 
 `-c` = Might need input files. instructs the compiler to perform a compilation but stop before linking
 
-`-d` = Needs argument(s). can be used several ways. does dissasembly,  specifies a directory to search for
+`-d` = Needs argument(s). can be used several ways. does disassembly,  specifies a directory to search for
 header files or provides additional debugging information.
 
 `-e` = Needs argument(s). used to emit preprocessed source code. `gcc -e myprogram.c -o myprogram.i`

using-gdb-debugger.md

@@ -0,0 +1,48 @@
+# using the GNU debugger gdb
+
+My version of the GNU debugger gdb is GNU gdb (Debian 8.2.1-2+b3) 8.2.1
+It is in /usr/bin/gdb /etc/gdb /usr/include/gdb /usr/share/gdb
+
+## lowercase flags
+
+`gdb -b` requires an argument. starts GDB in batch mode. `gdb -b <batch_file_name>`
+
+`gdb -c` requires an argument. allows you to specify a command to be executed immediately after GDB starts.
+
+`gdb -d` requires an argument. allows you to debug a running process `gdb -d <PID>`
+
+`gdb -e` requires an argument.  used to specify an environment variable to be set for the program being debugged.
+
+`gdb -f` starts the repl. used to specify a core file for debugging. `gdb -f <core_file_name>`
+
+`gdb -h` prints the help
+
+`gdb -i` requires an argument. used to start GDB in interactive mode. `gdb -i <program_name>`
+
+`gdb -l` requires an argument. not a common option flag.
+
+`gdb -n` starts the repl. not a common option flag
+
+`gdb -p` requires an argument. used to specify the PID (Process ID) of a running process that you want to attach to and debug.
+
+`gdb -q` used to suppress the initial startup message when launching GDB. just says (gdb).
+
+`gdb -r` starts the repl.  used to restart a program that has crashed or terminated abnormally.
+
+`gdb -s` requires an argument.  is a shorthand for the step command. `gdb -s <program_name>`
+
+`gdb -t` says option `-t` is ambiguous might be `-tui` or `-tty`
+
+`gdb -u` says option `-ui` requires an argument
+
+`gdb -v` prints the version
+
+`gdb -w` starts the repl. used to set watchpoints. `gdb -w <program_name>` from there you can use the watch command.
+
+`gdb -x` requires an argument. used to execute a GDB command script. `gdb -x <script_name> <program_name>`
+
+There's only 1 upperase flag
+
+`gdb -D` requires an argument. used to define preprocessor macros for the program being debugged
+
+Help is in `gdb --help` or `gdb -h`

using-gnu-ld-linker.md

@@ -54,7 +54,7 @@ My ld comes from /usr/bin/ld.gold /usr/bin/ld /usr/bin/ld.bfd /usr/share/man/man
 
 ## untested flags
 
-- ld -T       used to specifiy the linker file used
+- ld -T       used to specify the linker file used
 
 - ld -o       Specifies the name of the output file (executable or library) to be generated