《aix系统应用基础》04 files and d

There are two types of path names:
Absolute or Full Path Name (start from the / directory): $ vi /home/team01/doc/mon_report $ /usr/bin/ls –l /home/team01
Unit 4 Files and Directories
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4.1
Unit Objectives
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A File
● A file is:
– A collection of data – A stream of characters or a "byte stream" – No structure is imposed on a file by the operating system
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File Types
Relative Path Name (start from current directory):
$ cd /home/team01 $ vi doc/mon_report $ cd /usr/bin $ ./ls –l /home/team01
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Where Am I?
The print working directory command can be used to find out what your current directory is:
After completing this unit, you should be able to: ● Describe the different file types ● Describe the AIX file system structure ● Use full and relative path names in a file specification ● Create, delete, and list directories ● Use the touch command to create an empty file
The ls command with the -l option can be used to obtain more information about the files in a directory.
date
July 10 10:15 July 11 11:00
size loc 512 96
Data
$ vi myfile
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AIX File Systems
● Refers to both the physical and logical storage and access of files.
● In AIX, a file system is an allocation of storage. ● Similar in concept to partitions in the PC environment. ● Allows the operating system to store and retrieve the data
from files quickly and efficiently. ● To access file systems, we associate them with a directory.
● AIX has several pre-defined file systems:
/ (root) /usr /var /proc
Ordinary: Text or code data
Directory: A table of contents, that stores a list of files within that directory
Special Files: Represent hardware or logical devices Example: The CD-ROM device is accessed via the /dev/cd0 file.
/tmp /opt /home
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Hierarchical Structure
/
usr dev
etc
tty1
bin
lp0
sbin home var tmp opt proc
team01
team02
team03
test doc c
.profile manuals test1
mon_report trio_ltr walrus
reports
c
pgms
suba
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Path Names
A sequence of names, separated by slashes (/), that describes the path the system must follow to locate a file in the file system.
$ ls c doc manuals test1
$ ls –a . .. .profile c doc manuals test1
$ ls –R c doc manuals test1
./c: ./doc: Mon_report trio_ltr walrus
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Long Listing of Files
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Directory Contents
Directory
i-node Table
name i-node subdir1 4 myfile 10
# type mode links user group 4 dir 755 2 team01 staff 10 file 644 1 team01 staff
$ pwd /e/team01
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Listing Directories
Syntax: ls [ directory ]
Common options: -a: Show hidden files (files that start with a “.”) -R: List files in all subdirectories (recursively)