as is a generic command name for an assembler on Unix.

Implementations

More than one assembler for Unix and Unix-like operating systems has been implemented with an executable called as. Users may be able to determine which implementation (if any) is present on their system by consulting the system's manuals, or by running as --version.

AT&T / Bell Labs

As of November 1971, an assembler invoked as as was available for Unix. Implemented by Bell Labs staff, it was based upon the Digital Equipment Corporation's PAL-11R assembler.

GNU Assembler

Circa 1986, the

GNU Assembler The GNU Assembler, commonly known as gas or as, is the assembler developed by the GNU Project. It is the default back-end of GCC. It is used to assemble the GNU operating system and the Linux kernel, and various other software. It is a part o ...

("GAS") became available. As with the original UNIX assembler, GAS's executable is simply named as. As of 2018, GAS implements many features that were not present in the 1971 Bell Labs implementation.

References

Assemblers Unix programming tools {{Unix-stub