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| -rw-r--r-- | lib/README.curl_off_t | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/lib/README.curl_off_t b/lib/README.curl_off_t new file mode 100644 index 000000000..01316152b --- /dev/null +++ b/lib/README.curl_off_t @@ -0,0 +1,40 @@ + + curl_off_t explained + ==================== + +curl_off_t is a data type provided by the external libcurl include headers. It +is the type meant to be used for the curl_easy_setopt() options that end with +LARGE. The type is 64bit large on most modern platforms. + +Transition from < 7.19.0 to >= 7.19.0 +------------------------------------- + +Applications that used libcurl before 7.19.0 that is rebuilt with a libcurl +that is 7.19.0 or later may or may not have to worry about anything of +this. We have made a significant effort to make the transition really seamless +and transparant. + +You have have to take notice if you are in one of the following situations: + +o Your app is using or will after the transition use a libcurl that is built + with LFS (large file support) disabled even though your system otherwise + supports it. + +o Your app is using or will after the transition use a libcurl that doesn't + support LFS at all, but your system and compiler support 64bit data types. + +In both these cases, the curl_off_t type will now (after the transition) be +64bit where it previously were 32bit. This will cause a binary incompatibility +that you MAY need to deal with. + +Historicly +---------- + +Previously, before 7.19.0, the curl_off_t type would be rather strongly +connected to the size of the system off_t type, where currently curl_off_t is +independent of that. + +The strong connection to off_t made it troublesome for application authors +since when they did mistakes, they could get curl_off_t type of different +sizes in the app vs libcurl, and that caused strange effects that were hard to +track and detect by users of libcurl. |