dyld环境变量

转自：https://developer.apple.com/library/content/technotes/tn2239/_index.html#//apple_ref/doc/uid/DTS40010638-CH1-SUBSECTION21

Dynamic Linker (dyld)

The dynamic linker (dyld) supports a number of debugging facilities that you can enable via environment variables. These are fully documented in the manual page. Table 6 lists some of the more useful variables.

Table 6  Dynamic linker environment variables

Variable	Summary
DYLD_IMAGE_SUFFIX	Search for libraries with this suffix first
DYLD_PRINT_LIBRARIES	Log library loads
DYLD_PRINT_LIBRARIES_POST_LAUNCH	As above, but only after main has run
DYLD_PRINT_OPTS [1]	Print launch-time command line arguments
DYLD_PRINT_ENV [1]	Print launch-time environment variables
DYLD_PRINT_APIS [1]	Log dyld API calls (for example, dlopen)
DYLD_PRINT_BINDINGS [1]	Log symbol bindings
DYLD_PRINT_INITIALIZERS [1]	Log image initialization calls
DYLD_PRINT_SEGMENTS [1]	Log segment mapping
DYLD_PRINT_STATISTICS [1]	Print launch performance statistics

Notes:

1. On the Mac OS X side these are only available on Mac OS X 10.4 and later. They are, however, available on all versions of iOS.

While these environment variables are implemented on iOS, many of them have limited utility because of the restricted environment on that system.