#### 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`.