quartet over

Author: cirosantilli

.gitignore

@@ -1,29 +1,17 @@
-#docs, examples, tests (human manipulation only):
-_gitignore/
-
-#output files generated by a program:
+# Output and temporary files.
 _out/
-
-#intermediate compilation files: `.o`
 _tmp/
+*.tmp
 
-# Compiled Object files
+# Compiled stuff.
 *.slo
 *.lo
 *.out
 *.o
-
-# Compiled Dynamic libraries
 *.so
 *.dylib
-
-# Compiled Static libraries
 *.lai
 *.la
 *.a
-
-#assembly code
 *.s
 
-#temporary files
-*.tmp

README.md

@@ -6,27 +6,30 @@ Includes Linux concepts and utilities that work on Linux, not necessarily in the
 
 ## Index
 
-Important files:
-
 - [ubuntu/install](ubuntu/install.sh): Ubuntu install methods many programs.
 - [utils](utils.sh): dump of many utils that fit in no other category or are not large enough to get their own file. Many POSIX utilities.
 
 Documentation viewers:
 
 - [man](man.sh)
-- [info](info.sh)
+- [info](info.md)
 
 Base standards:
 
 - [POSIX](posix.md)
 - [Linux](linux.md)
 - [LSB](lsb.md)
 - [FHS](fhs.md)
+- [GNU](gnu.md)
 
 Kernel related:
 
-- [Kernel](kernel/)
-- [System Call](system-call/)
+-   [Kernel](kernel/)
+-   [System Call](system-call/)
+-   [sysctl](sysctl.md)
+-   [Special files](special-files.md): `proc`, `dev` and `sys` filesystems.
+    - [proc filesystem](proc-filesystem.md)
+    - [dev filesystem](dev-filesystem.md)
 
 Initialization:
 
@@ -36,11 +39,11 @@ Initialization:
 
 Base topics:
 
-- [Desktop](desktop/): X, XDG, GNOME, KDE and related utilities.
-- [Filesystem](filesystem.md): POSIX file permissions.
-- [File permissions](file-permissions.md): filesystem, hard disks, mounting, partitions.
-- [Special files](special-files.md): `proc`, `dev` and `sys` filesystems.
-- [Terminal](terminal.md): terminal emulators, ANSI escapes, control characters.
+-   [Filesystem](filesystem.md): POSIX file permissions.
+    - [Hardlink](hardlink.md)
+-   [File permissions](file-permissions.md): filesystem, hard disks, mounting, partitions.
+-   [Terminal](terminal.md): terminal emulators, ANSI escapes, control characters.
+    - [Guake](guake.sh)
 
 Basic stream and file manipulation:
 
@@ -58,32 +61,55 @@ Pagers:
 - [more](more.md)
 - [pg](pg.md)
 
+Text processing:
+
+- [awk](awk.sh)
+- [echo](echo.sh)
+- [column](column.md)
+- [cut](cut.sh)
+- [Eclipse](eclipse.md)
+- [expand](expand.md)
+- [paste](paste.md)
+- [printf](printf.sh)
+- [sed](sed.sh)
+- [tabs](tabs.md)
+- [wc](wc.md)
+
+Binary data viewers:
+
+- [hd](hd.md)
+- [hexdump](hexdump.md)
+- [od](od.md)
+
+Diff:
+
+- [comm](comm.md)
+- [cmp](cmp.md)
+- [diff](diff.md)
+- [wdiff](diff.md)
+
 Files, directories:
 
 -   [cp](cp.sh)
-
+-   [dd](dd.md)
 -   [du](du.md)
-
 -   [fdupes](fdupes.md)
-
 -   [find](find.md)
-
 -   links:
-
     - [ln](ln.md)
     - [readlink](readlink.md)
     - [realpath](realpath.md)
-
 -   [locate](locate.md)
-
 -   [ls](ls.md)
-
 -   [read](read.md)
-
 -   [stat](stat.md)
-
 -   [tree](tree.md)
 
+File managers:
+
+- [Krusader](krusader.md)
+- [vifm](vifm.md)
+
 Partitions, filesystems:
 
 - [badblocks](badblocks.md)
@@ -94,20 +120,15 @@ Partitions, filesystems:
 - [lsblk](lsblk.md)
 - [swap partition](swap-partition.md)
 
-Diff:
+[Compilation and libraries](compile.md):
 
-- [comm](comm.md)
-- [cmp](cmp.md)
-
-Binary data viewers:
-
-- [hd](hd.md)
-- [hexdump](hexdump.md)
-- [od](od.md)
+- [GDB](gdb.md)
+- [Library](library.md)
 
 Programming:
 
 - [ack](ack.sh)
+- [ctags](ctags/)
 - [Compile](compile/): compilation process, dynamic libraries.
 
 Processes:
@@ -117,6 +138,8 @@ Processes:
 - [free](env.md)
 - [htop](htop.md)
 - [jobs](jobs.sh)
+- [kill](kill.sh)
+- [killall](killall.sh)
 - [lsof](lsof.md)
 - [nice](nice.sh)
 - [nohup](nohup.sh)
@@ -139,13 +162,16 @@ Date and time:
 
 Media video, games, etc.) file types, viewers, editors, capture, synthesizers:
 
-- [Audio](audio/): audio, music, sound.
-- [Book](book.md): PDF, DJVU.
-- [Dictionary](dictionary.md): dictionary formats.
-- [Game](game.md): games, emulation.
-- [Image](image/): images, photos.
-- [Markup](markup/): Markdown, RST. Focus on command line interface and extensions.
-- [Video](video.md): videos, films, subtitles.
+-   [Audio](audio/): audio, music, sound.
+-   [Book](book.md): PDF, DJVU.
+-   [Dictionary](dictionary.md): dictionary formats.
+-   [Game](game.md): games, emulation.
+-   [Image](image/): images, photos.
+    - [GIMP](gimp.md)
+    - [gnuplot](gnuplot)
+    - [imagemagick](imagemagick.md)
+-   [Markup](markup/): Markdown, RST. Focus on command line interface and extensions.
+-   [Video](video.md): videos, films, subtitles.
 
 File sharing:
 
@@ -169,25 +195,49 @@ User operations:
 - [id](id.md)
 - [usermod](usermod.md)
 
+[Desktop](desktop/): X, XDG, GNOME, KDE and related utilities.
+
+-   Notifications
+    - [libnotify](libnotify.md)
+    - [zenity](zenity.md)
+-   [update-alternatives](update-alternatives.md)
+-   [xsel](xsel.md)
+-   [xdg-open](xdg-open.md)
+-   [xset](xset.md)
+
 Generic data formats:
 
 - [JSON](json.md)
-- [Unicode](unicode.md)
 - [XML](xml/)
 
+Character encoding:
+
+- [Unicode](unicode.md)
+    - [iconv](iconv.sh)
+
 Markup compilers:
 
 - [Kramdown](kramdown/)
 - [Pandoc](pandoc/)
 - [RST](rst/)
 
-Misc:
+[Virtual machine](virtual-machine/):
+
+- [Docker](docker/)
+- [Vagrant](vagrang/)
 
-- [eval](eval.sh)
+[Configuration automation](config-automation.md):
+
+- [chef](chef/)
+- [puppet](puppet.md)
+
+Misc:
 
-[Virtual machine](virtual-machine/): Vagrant, Docker.
+- [logrotate](logrotate.md)
+- [factor](factor.md)
+- [xargs](xargs.md)
 
-Related subjects in other repositories:
+## Related repositories
 
 - [Ubuntu Cheat](https://github.com/cirosantilli/ubuntu-cheat): Ubuntu specifics.
 - [C++ Cheat](https://github.com/cirosantilli/cpp-cheat): contains some compilation / language heavy subjects like the POSIX C API or generation of dynamic libraries.
@@ -204,3 +254,13 @@ For filenames:
 And concepts inside file content:
 
     git grep '#something'
+
+## WIP
+
+Compilation and libraries:
+
+- [gcov](gcov.md)
+
+Misc:
+
+- [sys-filesystem](sys-filesystem.md)

boot.md

@@ -95,6 +95,10 @@ Generated files and data after `sudo update-grub`:
 
 -   `GRUB_CMDLINE_LINUX_DEFAULT`: space separated list of Kernel boot parameters.
 
+    Documented at:
+
+        man bootparam
+
     Those parameters can also be edited from the boot menu for single session by selecting the partition and clicking `e`.
 
 	Most important to know:

chef/README.md

@@ -0,0 +1,31 @@
+# Chef
+
+Good intro tutorial: <http://gettingstartedwithchef.com/first-steps-with-chef.html>
+
+Important terms:
+
+-   cookbook: contains one ore more recipes, template files, etc.
+
+-   recipe: specifies how to take an action.
+
+-   chef-solo: version of the program that runs on a single computer.
+
+    Reads local configuration files and modifies the system.
+
+-   chef-client and chef-server: version of the program that runs in a client server system.
+
+    Normally, the server offers configuration files requested by the client, which uses them to modify the system it runs on.
+
+-   knife: program that can:
+
+    -   create cookbook templates:
+
+            knife cookbook create $COOKBOOK_NAME
+
+    -   download recipes so that chef-solo can use them:
+
+            knife cookbook site download $COOKBOOK_NAME
+
+    Does not resolve recipe dependencies.
+
+-   berkshelf: downloads recipes like knife, but also manages dependencies.

config-automation/chef/vagrant_called/.gitignore renamed to chef/vagrant_called/.gitignore

@@ -1,3 +1,5 @@
+# Vagrant called
+
 On this example, Vagrant invokes chef automatically at Vagrant up.
 
 All the chef configs including the `-j a.json` and `-c a.rb` files are inside `Vagrantfile`.

config-automation/chef/vagrant_called/README.md renamed to chef/vagrant_called/README.md

@@ -1,6 +1,6 @@
 # cmp
 
-GNU Diffutils package.
+<http://pubs.opengroup.org/onlinepubs/9699919799/utilities/cmp.html>, Ubuntu GNU Diffutils package.
 
 Compares F and G byte by byte, until first difference is found.
 

config-automation/chef/vagrant_called/Vagrantfile renamed to chef/vagrant_called/Vagrantfile

@@ -0,0 +1,29 @@
+# column
+
+`bsdmainutils` package.
+
+If the input would be larger than the current terminal column count, format it into newspaper like columns.
+
+    seq 100 | column
+
+Sample output:
+
+    1	6	11	16	21	26	31	36	41	46	51	56	61	66	71	76	81	86	91	96
+    2	7	12	17	22	27	32	37	42	47	52	57	62	67	72	77	82	87	92	97
+    3	8	13	18	23	28	33	38	43	48	53	58	63	68	73	78	83	88	93	98
+    4	9	14	19	24	29	34	39	44	49	54	59	64	69	74	79	84	89	94	99
+    5	10	15	20	25	30	35	40	45	50	55	60	65	70	75	80	85	90	95	100
+
+Options:
+
+- `-t`: format data into table format. Intelligently uses a separator char
+- `-s`: set the separator char
+
+Command:
+
+    printf '123|1|12345\n12345|123|1\n' | column -ts'|'
+
+Sample output:
+
+    123    1    12345
+    12345  123  1