* He joined Princeton’s CS department in 2000 but taught at least one class there as early as 1993 while still at Bell Labs Research (on sabbatical?)
* One of his students regularly brought a 386sx laptop (running pre-1.0 Linux) to class and when Brian was asked more obscure questions about what awk did which he couldn’t remember, the student would run commands in awk and feed Brian the definitive implementation answer. So Brian had some exposure to Linux moderately early on.
I'm not sure what you're thinking of, but there at least 3 prominent and still-relevant awk implementations:
nawk (One True Awk / AT&T awk / BWK awk): the original awk, still maintained; is used by macOS, FreeBSD, OpenBSD, and NetBSD https://github.com/onetrueawk/awk
There were some differences even in the mid 90s between AT&T-style awk which was then considered the original/definitive/most-backward-compatible and gawk which was new/shiny (although not /that/ new).
I believe both were available in Linux back then. I believe in the above anecdote both were consulted with the emphasis on AT&T-style awk for obvious reasons.
* He joined Princeton’s CS department in 2000 but taught at least one class there as early as 1993 while still at Bell Labs Research (on sabbatical?)
* One of his students regularly brought a 386sx laptop (running pre-1.0 Linux) to class and when Brian was asked more obscure questions about what awk did which he couldn’t remember, the student would run commands in awk and feed Brian the definitive implementation answer. So Brian had some exposure to Linux moderately early on.
* Here’s a writeup from him on putting AT&T’s toll free phone directory on the internet back in fall 1994: https://www.cs.princeton.edu/~bwk/800.html