diff options
Diffstat (limited to 'lib/kernel/doc/src/os.xml')
| -rw-r--r-- | lib/kernel/doc/src/os.xml | 77 |
1 files changed, 68 insertions, 9 deletions
diff --git a/lib/kernel/doc/src/os.xml b/lib/kernel/doc/src/os.xml index 739ac35d2a..7ce2f54542 100644 --- a/lib/kernel/doc/src/os.xml +++ b/lib/kernel/doc/src/os.xml @@ -4,14 +4,14 @@ <erlref> <header> <copyright> - <year>1997</year><year>2016</year> + <year>1997</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at - + http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software @@ -19,7 +19,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. - + </legalnotice> <title>os</title> @@ -38,17 +38,35 @@ most platforms.</p> </description> + <datatypes> + <datatype> + <name name="os_command"/> + </datatype> + <datatype> + <name name="os_command_opts"/> + <desc> + <p>Options for <seealso marker="#cmd/2"><c>os:cmd/2</c></seealso></p> + <taglist> + <tag><c>max_size</c></tag> + <item> + <p>The maximum size of the data returned by the <c>os:cmd</c> call. + See the <seealso marker="#cmd/2"><c>os:cmd/2</c></seealso> + documentation for more details.</p> + </item> + </taglist> + </desc> + </datatype> + </datatypes> + <funcs> <func> <name name="cmd" arity="1"/> + <name name="cmd" arity="2"/> <fsummary>Execute a command in a shell of the target OS.</fsummary> <desc> <p>Executes <c><anno>Command</anno></c> in a command shell of the - target OS, - captures the standard output of the command, and returns this - result as a string. This function is a replacement of - the previous function <c>unix:cmd/1</c>; they are equivalent on a - Unix platform.</p> + target OS, captures the standard output of the command, + and returns this result as a string.</p> <p><em>Examples:</em></p> <code type="none"> LsOut = os:cmd("ls"), % on unix platform @@ -57,6 +75,21 @@ DirOut = os:cmd("dir"), % on Win32 platform</code> called from another program (for example, <c>os:cmd/1</c>) can differ, compared with the standard output of the command when called directly from an OS command shell.</p> + <p><c>os:cmd/2</c> was added in kernel-5.5 (OTP-20.2.1). It makes it + possible to pass an options map as the second argument in order to + control the behaviour of <c>os:cmd</c>. The possible options are: + </p> + <taglist> + <tag><c>max_size</c></tag> + <item> + <p>The maximum size of the data returned by the <c>os:cmd</c> call. + This option is a safety feature that should be used when the command + executed can return a very large, possibly infinite, result.</p> + <code type="none"> +> os:cmd("cat /dev/zero", #{ max_size => 20 }). +[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]</code> + </item> + </taglist> </desc> </func> @@ -156,6 +189,33 @@ DirOut = os:cmd("dir"), % on Win32 platform</code> </func> <func> + <name name="set_signal" arity="2"/> + <fsummary>Enables or disables handling of OS signals.</fsummary> + <desc> + <p>Enables or disables OS signals.</p> + <p>Each signal my be set to one of the following options:</p> + <taglist> + <tag><c>ignore</c></tag> + <item> + This signal will be ignored. + </item> + + <tag><c>default</c></tag> + <item> + This signal will use the default signal handler for the operating system. + </item> + + <tag><c>handle</c></tag> + <item> + This signal will notify + <seealso marker="kernel_app#erl_signal_server"><c>erl_signal_server</c></seealso> + when it is received by the Erlang runtime system. + </item> + </taglist> + </desc> + </func> + + <func> <name name="system_time" arity="0"/> <fsummary>Current OS system time.</fsummary> <desc> @@ -296,4 +356,3 @@ calendar:now_to_universal_time(TS), </func> </funcs> </erlref> - |