The real explanation: stackoverflow.com/questions/1780599/what-is-the-meaning-of-posix/31865755#31865755
Overview by Ciro Santilli at: superuser.com/questions/284342/what-are-path-and-other-environment-variables-and-how-can-i-set-or-use-them/1864687#1864687
This section is about POSIX environment variable that have special effects.
They are documented by POSIX at: pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08
Some mentions by Ciro Santilli at: superuser.com/questions/284342/what-are-path-and-other-environment-variables-and-how-can-i-set-or-use-them/1864687#1864687
Non-POSIX only here.
If you are a programmer,
grep becomes a verb: "to grep" means "to search text files", much like "to Google" means "to search random stuff online".This is a weak point of grep, it can't handle large lines that don't fit fully into memory:
- superuser.com/questions/1703029/is-there-a-limit-for-a-line-length-for-grep-command-to-process-correctly what is the grep line limit?
- unix.stackexchange.com/questions/223078/best-way-to-grep-big-binary-file/758528#758528 Ciro's
bgrepcanon - large not required but mentioning bgrep anyways:
- superuser.com/questions/1368263/use-grep-for-a-long-line-to-get-the-part-of-the-line/1811969#1811969
- unix.stackexchange.com/questions/217936/equivalent-command-to-grep-binary-files/758544#758544
- stackoverflow.com/questions/2034799/how-to-truncate-long-matching-lines-returned-by-grep-or-ack/77263826#77263826
- stackoverflow.com/questions/9988379/how-to-grep-a-text-file-which-contains-some-binary-data leaving this one alone for now
- stackoverflow.com/questions/65674717/how-to-check-if-a-binary-file-is-contained-inside-another-binary-from-the-linux search pattern from file
Getting started tutorial: unix.stackexchange.com/questions/223078/best-way-to-grep-a-big-binary-file/758528#758528
Articles by others on the same topic
The Portable Operating System Interface standards specify interfaces and observable behaviour for portable programs, including file descriptors, hard links and unlinking an open file. Their requirements do not prescribe one on-storage inode layout. The worked examples below use POSIX Unix semantics for ordinary files. [ref]
https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap03.html. The Open Group, POSIX.1-2024, definitions of files, directories and file descriptors
// Target: computer-science.bigb