37.1.1 Dynamic Linker Diagnostics

The ‘ld.so --list-diagnostics’ produces machine-readable diagnostics output. This output contains system data that affects the behavior of the GNU C Library, and potentially application behavior as well.

The exact set of diagnostic items can change between releases of the GNU C Library. The output format itself is not expected to change radically.

The following table shows some example lines that can be written by the diagnostics command.

dl_pagesize=0x1000

The system page size is 4096 bytes.

env[0x14]="LANG=en_US.UTF-8"

This item indicates that the 21st environment variable at process startup contains a setting for LANG.

env_filtered[0x22]="DISPLAY"

The 35th environment variable is DISPLAY. Its value is not included in the output for privacy reasons because it is not recognized as harmless by the diagnostics code.

path.prefix="/usr"

This means that the GNU C Library was configured with --prefix=/usr.

path.system_dirs[0x0]="/lib64/"
path.system_dirs[0x1]="/usr/lib64/"

The built-in dynamic linker search path contains two directories, /lib64 and /usr/lib64.