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| author | John Högberg <[email protected]> | 2017-12-05 10:27:51 +0100 |
|---|---|---|
| committer | John Högberg <[email protected]> | 2018-01-03 08:14:29 +0100 |
| commit | 185a0cdc2d0f72d64768dc6dd5465ad6fe561028 (patch) | |
| tree | 6760728de2cc5e698b99ac3c35d101cbe199968d /erts/doc/src/erl_driver.xml | |
| parent | d469368b9e14b9834017a7cf318f02950a4aadcb (diff) | |
| download | otp-185a0cdc2d0f72d64768dc6dd5465ad6fe561028.tar.gz otp-185a0cdc2d0f72d64768dc6dd5465ad6fe561028.tar.bz2 otp-185a0cdc2d0f72d64768dc6dd5465ad6fe561028.zip | |
Document that os:putenv/2 and putenv(3) modify different environments
This is *ONLY* relevant for drivers/NIFs, so it's probably counter-
productive to document it elsewhere.
Diffstat (limited to 'erts/doc/src/erl_driver.xml')
| -rw-r--r-- | erts/doc/src/erl_driver.xml | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/erts/doc/src/erl_driver.xml b/erts/doc/src/erl_driver.xml index ca9d458e1e..c790872fe4 100644 --- a/erts/doc/src/erl_driver.xml +++ b/erts/doc/src/erl_driver.xml @@ -2304,8 +2304,13 @@ r = driver_async(myPort, &myKey, myData, myFunc); ]]></code> buffer is too small, a value > <c>0</c> is returned and <c>*value_size</c> has been set to the buffer size needed.</p> <warning> - <p>Do <em>not</em> use libc's <c>getenv</c> or similar C library - interfaces from a driver.</p> + <p>This function reads the emulated environment used by + <seealso marker="os:getenv/1"><c>os:getenv/1</c></seealso> and not + the environment used by libc's <c>getenv(3)</c> or similar. Drivers + that <em>require</em> that these are in sync will need to do so + themselves, but keep in mind that they are segregated for a reason; + <c>getenv(3)</c> and its friends are <em>not thread-safe</em> and + may cause unrelated code to misbehave or crash the emulator.</p> </warning> <p>This function is thread-safe.</p> </desc> @@ -2650,8 +2655,13 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0] environment variable is removed.</p> </note> <warning> - <p>Do <em>not</em> use libc's <c>putenv</c> or similar C library - interfaces from a driver.</p> + <p>This function modifies the emulated environment used by + <seealso marker="os:putenv/2"><c>os:putenv/2</c></seealso> and not + the environment used by libc's <c>putenv(3)</c> or similar. Drivers + that <em>require</em> that these are in sync will need to do so + themselves, but keep in mind that they are segregated for a reason; + <c>putenv(3)</c> and its friends are <em>not thread-safe</em> and + may cause unrelated code to misbehave or crash the emulator.</p> </warning> <p>This function is thread-safe.</p> </desc> |