NAME

as − assembler

SYNOPSIS

as [options] file

DESCRIPTION

The as command creates object files from assembly language source files.  and there are no unresolved external references.  The ­following flags may be specified in any order:

−o objfile Put the output of the assembly in objfile.  By default, the output file name is formed by removing the .s suffix, if there is one, from the input file name and appending a .o suffix. 

−n Turn off long/short address optimization.  By default, address optimization takes place. 

−m Run the m4 macro processor on the input to the assembler. 

−R Remove (unlink) the input file after assembly is completed. 

−dl Obsolete.  Assembler issues a warning saying that it is ignoring the −dl option. 

−T Accept obsolete assembler directives. 

−V Write the version number of the assembler being run on the standard error output. 

−Q{y|n} If −Qy is specified, place the version number of the assembler being run in the object file.  The default is −Qn. 

−Y [md],dir Find the m4 preprocessor (m) and/or the file of predefined macros (d) in directory dir instead of in the customary place. 

FILES

By default, as creates its temporary files in /var/tmp.  This location can be changed by setting the environment variable TMPDIR [see tempnam in tmpnam(3S)]. 

SEE ALSO

cc(1), ld(1), m4(1), nm(1), strip(1), tmpnam(3S), a.out(4)

NOTES

If the −m (m4 macro processor invocation) option is used, keywords for m4 [see m4(1)] cannot be used as symbols (variables, functions, labels) in the input file since m4 cannot determine which keywords are assembler symbols and which keywords are real m4 macros. 

The .align assembler directive may not work in the .text section when long/short address optimization is performed. 

Arithmetic expressions may only have one forward referenced symbol per expression. 

Whenever possible, you should access the assembler through a compilation ­system interface program such as cc. 

  —  C Development Set