Zed's bash cheatsheet

bash-cheatsheet.md

Bash cheatsheet

Reading: Oswald Campesato, Bash Command Line and Shell Scripts: Pocket Primer, (Dulles, VA: Mercury Learning and Information, 2020)

Basics

• history
• cat
• echo
• head -n 5|tail -n 5

ls

• -1 displays vertical list of file/dir names only
• -l is for "longlist"
• -t sorts entries by timestamp, in descending order (i.e. latest on top)
• -r reverses the sort order
• -tr sorts entries by timestamp, in ascending order (i.e. oldest on top)

Anatomy of ls -l output:

drwxr-xr-x  7 zeddee  staff   224 Aug 22 13:26 assets
lrwxr-xr-x  1 zeddee  staff    62 Aug 22 13:26 bash-cheatsheet.md -> /Users/zeddee/working/sites/bash-cheatsheet/bash-cheatsheet.md
-rw-r--r--  1 zeddee  staff   352 Aug 21 16:39 dead-dog.md
-rw-r--r--  1 zeddee  staff   115 Aug 21 20:16 house-with-locked-windows.md
-rw-r--r--  1 zeddee  staff  1141 Aug 20 23:58 moebius.md
-rw-r--r--  1 zeddee  staff   205 Aug 21 16:34 sparkfile-aug-2020.md

• drwxr-xr-x: filetype and permissions for file
  • first char is file "type":
    • -: Regular file. E.g., ASCII text file, binary, hard link.
    • b: Block special file (physical hard drive) (??).
    • c: Character special file (physical hard drive) (?).
    • d: A directory.
    • l: A symbolic link.
    • p: A named pipe.
    • s: A socket.
• 7: Number of memory blocks occupied by this file or dir.
• zeddee: Owner of the file.
• staff: Group that owns the file.
• 224: File size in bytes.
• Aug 22 13:26: Timestamp.
• assets: File or dir name.