87 lines
4.1 KiB
C
87 lines
4.1 KiB
C
/****************************************************************************
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* libs/libc/unistd/lib_getopt.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include "unistd.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: getopt
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*
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* Description:
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* getopt() parses command-line arguments. Its arguments argc and argv
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* are the argument count and array as passed to the main() function on
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* program invocation. An element of argv that starts with '-' is an
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* option element. The characters of this element (aside from the initial
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* '-') are option characters. If getopt() is called repeatedly, it
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* returns successively each of the option characters from each of the
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* option elements.
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*
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* If getopt() finds another option character, it returns that character,
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* updating the external variable optind and a static variable nextchar so
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* that the next call to getopt() can resume the scan with the following
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* option character or argv-element.
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*
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* If there are no more option characters, getopt() returns -1. Then optind
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* is the index in argv of the first argv-element that is not an option.
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*
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* The 'optstring' argument is a string containing the legitimate option
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* characters. If such a character is followed by a colon, this indicates
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* that the option requires an argument. If an argument is required for an
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* option so getopt() places a pointer to the following text in the same
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* argv-element, or the text of the following argv-element, in optarg.
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*
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* NOTES:
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* 1. opterr is not supported and this implementation of getopt() never
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* printfs error messages.
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* 2. getopt is NOT threadsafe!
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* 3. This version of getopt() does not reset global variables until
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* -1 is returned. As a result, your command line parsing loops
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* must call getopt() repeatedly and continue to parse if other
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* errors are returned ('?' or ':') until getopt() finally returns -1.
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* (You can also set optind to -1 to force a reset).
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* 4. Standard getopt() permutes the contents of argv as it scans, so that
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* eventually all the nonoptions are at the end. This implementation
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* does not do this.
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*
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* Returned Value:
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* If an option was successfully found, then getopt() returns the option
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* character. If all command-line options have been parsed, then getopt()
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* returns -1. If getopt() encounters an option character that was not
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* in optstring, then '?' is returned. If getopt() encounters an option
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* with a missing argument, then the return value depends on the first
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* character in optstring: if it is ':', then ':' is returned; otherwise
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* '?' is returned.
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*
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****************************************************************************/
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int getopt(int argc, FAR char * const argv[], FAR const char *optstring)
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{
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return getopt_common(argc, argv, optstring, NULL, NULL, GETOPT_MODE);
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}
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