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author | Lukas Larsson <[email protected]> | 2016-09-05 17:08:40 +0200 |
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committer | Lukas Larsson <[email protected]> | 2016-09-05 17:08:40 +0200 |
commit | bb8d105fd6d5b09097dc64b341d63f0f8d7e8906 (patch) | |
tree | c3525db7d9b99e3048eedf3f6a16fe2cb46689e9 /lib/kernel/src/os.erl | |
parent | c26f34c7c8940de2ade904d86e581f2c7463549f (diff) | |
parent | c0ed19c1261ee281d3c8f36ec3f28fa7328f0f39 (diff) | |
download | otp-bb8d105fd6d5b09097dc64b341d63f0f8d7e8906.tar.gz otp-bb8d105fd6d5b09097dc64b341d63f0f8d7e8906.tar.bz2 otp-bb8d105fd6d5b09097dc64b341d63f0f8d7e8906.zip |
Merge branch 'lukas/kernel/os_cmd_fix_stdin_close/OTP-13867' into maint
* lukas/kernel/os_cmd_fix_stdin_close/OTP-13867:
kernel: Close stdin of commands run in os:cmd
Diffstat (limited to 'lib/kernel/src/os.erl')
-rw-r--r-- | lib/kernel/src/os.erl | 14 |
1 files changed, 13 insertions, 1 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) -> |