GNU m4, version 1.4

A powerful macro processor

Edition 1.4, November 1994

• Introduction and preliminaries
  • Introduction to m4
  • Historical references
  • Invoking m4
  • Problems and bugs
  • Using this manual
• Lexical and syntactic conventions
  • Names
  • Quoted strings
  • Other tokens
  • Comments
• How to invoke macros
  • Macro invocation
  • Preventing macro invocation
  • Macro arguments
  • Quoting macro arguments
  • Macro expansion
• How to define new macros
  • Defining a macro
  • Arguments to macros
  • Special arguments to macros
  • Deleting a macro
  • Renaming macros
  • Temporarily redefining macros
  • Indirect call of macros
  • Indirect call of builtins
• Conditionals, loops and recursion
  • Testing macro definitions
  • Comparing strings
  • Loops and recursion
• How to debug macros and input
  • Displaying macro definitions
  • Tracing macro calls
  • Controlling debugging output
  • Saving debugging output
• Input control
  • Deleting whitespace in input
  • Changing the quote characters
  • Changing comment delimiters
  • Changing the lexical structure of words
  • Saving input
• File inclusion
  • Including named files
  • Searching for include files
• Diverting and undiverting output
  • Diverting output
  • Undiverting output
  • Diversion numbers
  • Discarding diverted text
• Macros for text handling
  • Calculating length of strings
  • Searching for substrings
  • Searching for regular expressions
  • Extracting substrings
  • Translating characters
  • Substituting text by regular expression
  • Formatted output
• Macros for doing arithmetic
  • Decrement and increment operators
  • Evaluating integer expressions
• Running UNIX commands
  • Executing simple commands
  • Reading the output of commands
  • Exit codes
  • Making names for temporary files
• Miscellaneous builtin macros
  • Printing error messages
  • Exiting from m4
• Fast loading of frozen states
• Compatibility with other versions of m4
  • Extensions in GNU m4
  • Facilities in System V m4 not in GNU m4
  • Other incompatibilities
• Concept index
• Macro index