getconf

List all configuration values available

$ getconf -a

$ getconf -a [path/to/directory]

$ getconf LONG_BIT

$ getconf CHILD_MAX

$ getconf -a | grep MAX

getconf [-v spec] systemvar_
getconf [-v spec] pathvar pathname_

getconf retrieves system configuration variables defined by POSIX and system-specific extensions. These values represent system limits and capabilities that applications can query to adapt their behavior.
Variables fall into two categories: system-wide values (like CHILDMAX, PAGESIZE) and pathname-specific values (like PATHMAX, NAMEMAX) that may vary by filesystem.
This is useful for shell scripts that need to query system limits without hardcoding values, ensuring portability across different systems.

-a

Display all configuration variables and their values

Use specification SPEC for configuration values

Number of bits in a long integer (32 or 64)

Maximum number of processes per user

Maximum number of files a process can have open

System memory page size in bytes

Maximum length of a file path

Maximum length of a hostname

Number of processors currently online

Some values may be indeterminate (shown as "undefined"). Pathname-specific variables can return different values for different filesystems. Not all variables are supported on all systems.

getconf is part of the POSIX standard and has been available on Unix-like systems since the early 1990s. It provides a standardized way to query the same configuration values that the C functions sysconf(), pathconf(), and confstr() return.

sysctl(8), ulimit(1), nproc(1)