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| author | Lukas Larsson <[email protected]> | 2016-09-02 14:29:26 +0200 |
|---|---|---|
| committer | Lukas Larsson <[email protected]> | 2016-09-02 16:34:56 +0200 |
| commit | c0ed19c1261ee281d3c8f36ec3f28fa7328f0f39 (patch) | |
| tree | c0bc86162e6a429289245b0da5cfc0901f9ebfbf /lib/kernel/src/os.erl | |
| parent | 71894a879d6254693791585246ce340dd7414b82 (diff) | |
| download | otp-c0ed19c1261ee281d3c8f36ec3f28fa7328f0f39.tar.gz otp-c0ed19c1261ee281d3c8f36ec3f28fa7328f0f39.tar.bz2 otp-c0ed19c1261ee281d3c8f36ec3f28fa7328f0f39.zip | |
kernel: Close stdin of commands run in os:cmd
This is needed when running programs that only exit when
stdin has been closed, e.g. 'more'.
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) -> |