Classic Shell Scripting

Chapter 10. Working with Files

In this chapter, we discuss some of the more common commands for working with files: how to list files, modify their timestamps, create temporary files, find files in a directory hierarchy, apply commands to a list of files, determine the amount of filesystem space used, and compare files.

Listing Files

The echo command provides one simple way to list files that match a pattern:

$ echo /bin/*sh                          
            Show shells in /bin
/bin/ash /bin/bash /bin/bsh /bin/csh /bin/ksh /bin/sh /bin/tcsh /bin/zsh

The shell replaces the wildcard pattern with a list of matching files, and echo displays them in a space-separated list on a single line. However, echo does not interpret its arguments further, and thus does not associate them with files in the filesystem.-

ls

Usage

ls [ options ] [ file(s) ]

Purpose

List the contents of file directories.

Major options

 

1

Digit one. Force single-column output. In interactive mode, ls normally uses multiple columns of minimal width to fit the current window.

-a

Show all files, including hidden files (those whose names begin with a dot).

-d

Print information about directories themselves, rather than about files that they contain.

-F

Mark certain file types with special suffix characters.

-g

Group only: omit the owner name (implies -l (lowercase L)).

-i

List inode numbers.

-L

Follow symbolic links, listing the files that they point to.

-l

Lowercase L. List in long form, with type, protection, owner, group, byte count, last modification time, and filename.

-r

Reverse ...