Sirraide b4e39e4ff9
[LLVM] [Support] Query the terminal width using ioctl() (#143514)
On unix systems, we were trying to determine the terminal width using
the `COULMNS` environment variable. Unfortunately, `COLUMNS` is not 
exported by all shells and thus not available on some systems.

We were previously using `ioctl()` for this; fall back to doing so if `COLUMNS`
does not exist or does not store a positive integer.

This essentially reverts a3eb3d3d92d037fe3c9deaad87f6fc42fe9ea766 and
parts of https://reviews.llvm.org/D61326.

For more information, see #139499.

Fixes #139499.
2025-06-17 15:03:37 +02:00
..

llvm/lib/Support/Unix README
===========================

This directory provides implementations of the lib/System classes that
are common to two or more variants of UNIX. For example, the directory
structure underneath this directory could look like this:

Unix           - only code that is truly generic to all UNIX platforms
  Posix        - code that is specific to Posix variants of UNIX
  SUS          - code that is specific to the Single Unix Specification
  SysV         - code that is specific to System V variants of UNIX

As a rule, only those directories actually needing to be created should be
created. Also, further subdirectories could be created to reflect versions of
the various standards. For example, under SUS there could be v1, v2, and v3
subdirectories to reflect the three major versions of SUS.