diff options
| -rw-r--r-- | lib/kernel/src/os.erl | 14 | ||||
| -rw-r--r-- | lib/kernel/test/os_SUITE.erl | 17 | ||||
| -rw-r--r-- | lib/kernel/test/os_SUITE_data/Makefile.src | 8 | ||||
| -rw-r--r-- | lib/kernel/test/os_SUITE_data/my_fds.c | 9 |
4 files changed, 43 insertions, 5 deletions
diff --git a/lib/kernel/src/os.erl b/lib/kernel/src/os.erl index 05bbf1069e..f8519d3a5e 100644 --- a/lib/kernel/src/os.erl +++ b/lib/kernel/src/os.erl @@ -254,7 +254,19 @@ mk_cmd(_,Cmd) -> {"/bin/sh -s unix:cmd", [out], %% We insert a new line after the command, in case the command %% contains a comment character. - ["(", unicode:characters_to_binary(Cmd), "\n); echo \"\^D\"\n"], + %% + %% The </dev/null closes stdin, which means that programs + %% that use a closed stdin as an termination indicator works. + %% An example of such a program is 'more'. + %% + %% The "echo ^D" is used to indicate that the program has executed + %% and we should return any output we have gotten. We cannot use + %% termination of the child or closing of stdin/stdout as then + %% starting background jobs from os:cmd will block os:cmd. + %% + %% I tried changing this to be "better", but got bombarded with + %% backwards incompatibility bug reports, so leave this as it is. + ["(", unicode:characters_to_binary(Cmd), "\n) </dev/null; echo \"\^D\"\n"], <<$\^D>>}. validate(Atom) when is_atom(Atom) -> diff --git a/lib/kernel/test/os_SUITE.erl b/lib/kernel/test/os_SUITE.erl index 19ab3713a1..ef252b732d 100644 --- a/lib/kernel/test/os_SUITE.erl +++ b/lib/kernel/test/os_SUITE.erl @@ -25,7 +25,7 @@ -export([space_in_cwd/1, quoting/1, cmd_unicode/1, space_in_name/1, bad_command/1, find_executable/1, unix_comment_in_command/1, deep_list_command/1, large_output_command/1, background_command/0, background_command/1, - message_leak/1, perf_counter_api/1]). + message_leak/1, close_stdin/0, close_stdin/1, perf_counter_api/1]). -include_lib("common_test/include/ct.hrl"). @@ -37,7 +37,7 @@ all() -> [space_in_cwd, quoting, cmd_unicode, space_in_name, bad_command, find_executable, unix_comment_in_command, deep_list_command, large_output_command, background_command, message_leak, - perf_counter_api]. + close_stdin, perf_counter_api]. groups() -> []. @@ -54,7 +54,8 @@ init_per_group(_GroupName, Config) -> end_per_group(_GroupName, Config) -> Config. -init_per_testcase(background_command, Config) -> +init_per_testcase(TC, Config) + when TC =:= background_command; TC =:= close_stdin -> case os:type() of {win32, _} -> {skip,"Should not work on windows"}; @@ -302,6 +303,16 @@ message_leak(_Config) -> process_flag(trap_exit, false). +%% Test that os:cmd closes stdin of the program that is executed +close_stdin() -> + [{timetrap, {seconds, 5}}]. +close_stdin(Config) -> + DataDir = proplists:get_value(data_dir, Config), + Fds = filename:join(DataDir, "my_fds"), + + "-1" = os:cmd(Fds). + + %% Test that the os:perf_counter api works as expected perf_counter_api(_Config) -> diff --git a/lib/kernel/test/os_SUITE_data/Makefile.src b/lib/kernel/test/os_SUITE_data/Makefile.src index 912d0cbcb1..f83f781411 100644 --- a/lib/kernel/test/os_SUITE_data/Makefile.src +++ b/lib/kernel/test/os_SUITE_data/Makefile.src @@ -3,7 +3,7 @@ LD = @LD@ CFLAGS = @CFLAGS@ -I@erl_include@ @DEFS@ CROSSLDFLAGS = @CROSSLDFLAGS@ -PROGS = my_echo@exe@ +PROGS = my_echo@exe@ my_fds@exe@ all: $(PROGS) @@ -12,3 +12,9 @@ my_echo@exe@: my_echo@obj@ my_echo@obj@: my_echo.c $(CC) -c -o my_echo@obj@ $(CFLAGS) my_echo.c + +my_fds@exe@: my_fds@obj@ + $(LD) $(CROSSLDFLAGS) -o my_fds my_fds@obj@ @LIBS@ + +my_fds@obj@: my_fds.c + $(CC) -c -o my_fds@obj@ $(CFLAGS) my_fds.c diff --git a/lib/kernel/test/os_SUITE_data/my_fds.c b/lib/kernel/test/os_SUITE_data/my_fds.c new file mode 100644 index 0000000000..704a4d1e1d --- /dev/null +++ b/lib/kernel/test/os_SUITE_data/my_fds.c @@ -0,0 +1,9 @@ +#include <stdio.h> + +int +main(int argc, char** argv) +{ + char buff[1]; + int res = read(stdin, buff, 1); + printf("%d", res); +} |