CT320: Network and System Administration

Fall 2019

Plain Text

Plain Text

$ echo "abcd" >foo
$ echo "fg" >>foo
$ ls -l foo
-rw------- 1 ct320 class 8 Mar 28 05:38 foo
$ cat foo
abcd
fg
$ od -t x1 foo
0000000 61 62 63 64 0a 66 67 0a
0000010

Windows Text Files—not what we want

What Plain Text is Not

Examples

$ date >good
$ cat good
Thu Mar 28 05:38:46 MDT 2024
$ ls -l good
-rw------- 1 ct320 class 29 Mar 28 05:38 good
$ file good
good: ASCII text

$ file /usr/share/cups/data/default.pdf
/usr/share/cups/data/default.pdf: PDF document, version 1.5

$ echo -n "hi" >bad
$ cat bad
hi$ ls -l bad
-rw------- 1 ct320 class 2 Mar 28 05:38 bad
$ file bad
bad: ASCII text, with no line terminators

$ sed 's/$/\r/' <good >bad
$ cat bad
Thu Mar 28 05:38:46 MDT 2024

$ ls -l  bad good
-rw------- 1 ct320 class 30 Mar 28 05:38 bad
-rw------- 1 ct320 class 29 Mar 28 05:38 good
$ od -t x1 bad
0000000 54 68 75 20 4d 61 72 20 32 38 20 30 35 3a 33 38
0000020 3a 34 36 20 4d 44 54 20 32 30 32 34 0d 0a
0000036
$ od -t x1 good
0000000 54 68 75 20 4d 61 72 20 32 38 20 30 35 3a 33 38
0000020 3a 34 36 20 4d 44 54 20 32 30 32 34 0a
0000035
$ file bad
bad: ASCII text, with CRLF line terminators

Linux Text Editors

There are many text editors on Linux:

Where’s the GUI?