Split pagers, ddate and swap partition

Author: cirosantilli

README.md

@@ -44,10 +44,18 @@ Basic stream and file manipulation:
 
 - [cat](cat.md)
 - [head](head.md)
+- [rev](rev.sh)
+- [pr](pr.md)
 - [tac](tac.md)
 - [tail](tail.md)
 - [truncate](truncate.md)
 
+Pagers:
+
+- [less](less.md)
+- [more](more.md)
+- [pg](pg.md)
+
 File and directories:
 
 - [cp](cp.sh)
@@ -56,6 +64,7 @@ File and directories:
 - [find](find.md)
 - [locate](locate.md)
 - [ls](ls.md)
+- [Swap partition](swap-partition.md)
 - [tree](tree.md)
 
 Diff:
@@ -95,6 +104,7 @@ Processes:
 Date and time:
 
 - [cal](cal.md)
+- [ddate](ddate.md)
 - [date](date.md)
 - [hwclock](hwclock.md)
 - [Time zone](time-zone.md)

ddate.md

@@ -0,0 +1,11 @@
+# ddate
+
+Discordian calendar date: <http://en.wikipedia.org/wiki/Discordian_calendar>!
+
+`utils-linux` package.
+
+Likely an atheist programmer tongue-in-the-cheek.
+
+Sample output:
+
+    Today is Boomtime, the 32nd day of Chaos in the YOLD 3181

filesystem.md

@@ -275,44 +275,6 @@ List all parameters:
 
     sudo tune2fs -l /dev/sda5
 
-## mkswap
-
-## Swap partition
-
-The swap partition is used by OS to store RAM that is not being used at the moment to make room for more RAM.
-
-Should be as large as your RAM more or less, or twice it.
-
-Can be shared by multiple OS, since only one OS can run at a time.
-
-Make swap partition on a file in local filesystem:
-
-    sudo dd if=/dev/zero of=/swapfile bs=1024 count=1024k
-    sudo mkswap /swapfile
-    sudo swapon /swapfile
-
-For that to work every time:
-
-    sudo bash -c 'echo "/swapfile    none  swap  sw   0    0" >> /etc/fstab'
-
-Turn swap on on partition `/dev/sda7`:
-
-    sudo swapon /dev/sda7
-
-Find the currently used swap partition:
-
-    swapon -s
-
-Disable swapping:
-
-    sudo swapoff
-
-Make a swap partition on partition with random UUID.
-
-    sudo mkswap -U random /dev/sda7
-
-Swap must be off.
-
 ## gparted
 
 GUI to `fdisk` + `mke2fs.`
@@ -473,7 +435,9 @@ Get all devices:
 
 ## blkid
 
-Get UUID, label and filesystem type for all partitions
+`util-linux` package.
+
+Get UUID, label and filesystem type for all partitions:
 
     sudo blkid
 

less.md

@@ -0,0 +1,46 @@
+# less
+
+`less` package.
+
+Best pager available on all distributions.
+
+Advantages over Vim:
+
+- loads faster
+
+Disadvantages over Vim:
+
+- much less powerful
+
+Inputs:
+
+-   `/`: search forward
+
+-   `n`: repeat last search
+
+-   `d`: down one page
+
+-   `u`: up one page
+
+-   `g`: top of document
+
+-   `G`: bottom of document
+
+-   `g`: top of document
+
+-   `<ENTER>`: down one line
+
+-   `-S` : toggle line wrapping
+
+        less "$f"
+        printf 'ab\ncd\n' | less
+
+-   `-R` : interpret ANSI color codes
+
+    Rubbish:
+
+        ls --color | less
+
+    Colors!:
+
+        ls --color | less -R

more.md

@@ -0,0 +1,7 @@
+# more
+
+`util-linux` package.
+
+Like `less` but worse:
+
+	echo a | more

pg.md

@@ -0,0 +1,7 @@
+# pg
+
+`util-linux` package.
+
+Like `more` but worse:
+
+	echo a | pg

pr.md

@@ -0,0 +1,39 @@
+# pr
+
+Coreutils.
+
+Break file into pages with a certain number of lines and print to stdout:
+
+    seq 200 | pr
+
+Real old school.
+
+Sample abridged output:
+
+    2015-02-01 13:23                                                  Page 1
+
+
+    1
+    2
+    3
+    ...
+    55
+    56
+
+
+
+
+
+
+
+    2015-02-01 13:23                                                  Page 2
+
+
+    57
+    58
+    59
+    60
+    61
+    62
+    63
+    ...

rev.sh

@@ -0,0 +1,7 @@
+## rev
+
+  # Reverse input byte-wise:
+
+    [ "$(printf 'ab' | rev)" = 'ba' ] || exit 1
+
+  # `util-linux` package.

swap-partition.md

@@ -0,0 +1,45 @@
+# Swap partition
+
+The swap partition is used by OS to store RAM that is not being used at the moment to make room for more RAM.
+
+Should be as large as your RAM more or less, or twice it.
+
+Can be shared by multiple OS, since only one OS can run at a time.
+
+## mkswap
+
+`util-linux` package.
+
+Make swap partition on a file in local filesystem:
+
+    sudo dd if=/dev/zero of=/swapfile bs=1024 count=1024k
+    sudo mkswap /swapfile
+    sudo swapon /swapfile
+
+For that to work every time:
+
+    sudo bash -c 'echo "/swapfile    none  swap  sw   0    0" >> /etc/fstab'
+
+## swapon
+
+Turn swap on on partition `/dev/sda7`:
+
+    sudo swapon /dev/sda7
+
+Find the currently used swap partition:
+
+    swapon -s
+
+## swapoff
+
+Disable swapping:
+
+    sudo swapoff
+
+---
+
+Make a swap partition on partition with random UUID.
+
+    sudo mkswap -U random /dev/sda7
+
+Swap must be off.

util-linux.md

@@ -0,0 +1,5 @@
+# util-linux
+
+Project that provides several fundamental Linux utilities.
+
+Present on almost all distributions.