Node:Word Expansion, Previous:Regular Expressions, Up:Pattern Matching

Shell-Style Word Expansion

Word expansion means the process of splitting a string into words and substituting for variables, commands, and wildcards just as the shell does.

For example, when you write ls -l foo.c, this string is split into three separate words--ls, -l and foo.c. This is the most basic function of word expansion.

When you write ls *.c, this can become many words, because the word *.c can be replaced with any number of file names. This is called wildcard expansion, and it is also a part of word expansion.

When you use echo $PATH to print your path, you are taking advantage of variable substitution, which is also part of word expansion.

Ordinary programs can perform word expansion just like the shell by calling the library function wordexp.

• Expansion Stages: What word expansion does to a string.
• Calling Wordexp: How to call wordexp.
• Flags for Wordexp: Options you can enable in wordexp.
• Wordexp Example: A sample program that does word expansion.
• Tilde Expansion: Details of how tilde expansion works.
• Variable Substitution: Different types of variable substitution.