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nuttx/libs/libc/unistd/lib_getopt_common.c
Takumi Ando d0dd2684ce libc/unistd: getopt: Use argc to end parsing 
It should end parsing with argc even the argv are remaining
or it may access to invalid address.

Signed-off-by: Takumi Ando <t-ando@advaly.co.jp>
2021-12-15 12:02:59 -06:00

643 lines
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/****************************************************************************
* libs/libc/unistd/lib_getopt_common.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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
* distributed under the License is distributed on an "AS IS" BASIS, 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <stdbool.h>
#include <string.h>
#include "unistd.h"
/****************************************************************************
* Prive Functions
****************************************************************************/
/****************************************************************************
* Name: compare_long_option
*
* Description:
* Compare a command argument with a long option, handling the cases:
*
* --option: Any argument is in the next argv entry
* --option=argument: The argument is in the same argv entry
*
****************************************************************************/
static int compare_long_option(FAR const char *cmdarg,
FAR const char *optname,
FAR const char **argument)
{
int result;
*argument = NULL;
for (; ; )
{
int rawchar = *cmdarg++;
int optchar = *optname++;
int cmdchar;
/* The command line option may terminate with either '\0' or '='. */
cmdchar = rawchar;
if (cmdchar == '=')
{
cmdchar = '\0';
}
/* Perform the comparison */
result = cmdchar - optchar;
if (result != 0 || cmdchar == '\0')
{
/* If the '=' is the real terminator, then return the argument
* that follows the '='
*/
if (rawchar == '=')
{
*argument = cmdarg;
}
break;
}
}
return result;
}
/****************************************************************************
* Name: getopt_long_option
*
* Description:
* Handle one long option
*
****************************************************************************/
static int getopt_long_option(FAR struct getopt_s *go,
FAR char * const argv[],
FAR const struct option *longopts,
FAR int *longindex)
{
int ndx;
int ret;
/* The option list may not be NULL in this context */
if (longopts == NULL)
{
goto errout;
}
/* Search the list of long options for a matching name.
* The last element of the option arry must be filled with zeroes.
*/
for (ndx = 0; longopts[ndx].name != NULL; ndx++)
{
FAR char *terminator = NULL;
if (compare_long_option(go->go_optptr, longopts[ndx].name,
(FAR const char **)&terminator) == 0)
{
/* Found the option with the matching name. Does it have an
* argument provided in the same argv entry like
* --option=argument?
*/
if (terminator != NULL)
{
/* Skip over the option + argument */
go->go_optptr = NULL;
go->go_optind++;
switch (longopts[ndx].has_arg)
{
case no_argument:
/* But no argument is expected! */
go->go_optarg = NULL;
return '?';
case optional_argument:
case required_argument:
/* Return the required argument */
go->go_optarg = terminator;
break;
default:
goto errout;
break;
}
}
else
{
/* Does the option have a required argument in the next argv
* entry? An optional argument?
*/
switch (longopts[ndx].has_arg)
{
FAR char *next;
case no_argument:
/* No, no arguments. Just return the argument that we
* found.
*/
go->go_optptr = NULL;
go->go_optind++;
break;
case optional_argument:
/* Check if there is a following argument and if that
* following argument is another option.
*/
next = argv[go->go_optind + 1];
if (next == NULL || next[0] == '-')
{
go->go_optptr = NULL;
go->go_optarg = NULL;
go->go_optind++;
break;
}
/* Fall through and treat as a required option */
case required_argument:
/* Verify that the required argument is present */
next = argv[go->go_optind + 1];
if (next == NULL || next[0] == '-')
{
go->go_optptr = NULL;
go->go_optarg = NULL;
go->go_optind++;
return '?';
}
/* Return the required argument */
go->go_optptr = NULL;
go->go_optarg = next;
go->go_optind += 2;
break;
default:
goto errout;
break;
}
}
/* Setup return value.
*
* 'val' is the value to return on success, or to load into the
* variable pointed to by flag.
*
* 'flag' specifies how results are returned for a long option. If
* flag is NULL, then getopt_long() returns val. Otherwise,
* getopt_long() returns 0, and flag points to a variable which is
* set to val if the option is found, but left unchanged if the
* option is not found.
*/
if (longopts[ndx].flag != NULL)
{
*(longopts[ndx].flag) = longopts[ndx].val;
ret = OK;
}
else
{
ret = longopts[ndx].val;
}
/* If longindex is not NULL, it points to a variable which is
* set to the index of the long option relative to longopts.
*/
if (longindex != NULL)
{
*longindex = ndx;
}
return ret;
}
}
/* This option is not in the list of valid options */
go->go_optopt = *go->go_optptr;
return '?';
errout:
/* Restore the initial, uninitialized state */
go->go_binitialized = false;
return ERROR;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: getopt_common
*
* Description:
*
* getopt_common() is the common, internal implementation of getopt(),
* getopt_long(), and getopt_long_only().
*
* getopt() parses command-line arguments. Its arguments argc and argv
* are the argument count and array as passed to the main() function on
* program invocation. An element of argv that starts with '-' is an
* option element. The characters of this element (aside from the initial
* '-') are option characters. If getopt() is called repeatedly, it
* returns successively each of the option characters from each of the
* option elements.
*
* If getopt() finds another option character, it returns that character,
* updating the external variable optind and a static variable nextchar so
* that the next call to getopt() can resume the scan with the following
* option character or argv-element.
*
* If there are no more option characters, getopt() returns -1. Then optind
* is the index in argv of the first argv-element that is not an option.
*
* The 'optstring' argument is a string containing the legitimate option
* characters. If such a character is followed by a colon, this indicates
* that the option requires an argument. If an argument is required for an
* option so getopt() places a pointer to the following text in the same
* argv-element, or the text of the following argv-element, in optarg.
*
* The getopt_long() function works like getopt() except that it also
* accepts long options, started with two dashes. (If the program accepts
* only long options, then optstring should be specified as an empty
* string (""), not NULL.) Long option names may be abbreviated if the
* abbreviation is unique or is an exact match for some defined option
*
* getopt_long_only() is like getopt_long(), but '-' as well as "--" can
* indicate a long option. If an option that starts with '-' (not "--")
* doesn't match a long option, but does match a short option, it is
* parsed as a short option instead.
*
* NOTES:
* 1. opterr is not supported and this implementation of getopt() never
* printfs error messages.
* 2. getopt is NOT threadsafe!
* 3. This version of getopt() does not reset global variables until
* -1 is returned. As a result, your command line parsing loops
* must call getopt() repeatedly and continue to parse if other
* errors are returned ('?' or ':') until getopt() finally returns -1.
* (You can also set optind to -1 to force a reset).
* 4. Standard getopt() permutes the contents of argv as it scans, so that
* eventually all the nonoptions are at the end. This implementation
* does not do this.
*
* Returned Value:
* If an option was successfully found, then getopt() returns the option
* character. If all command-line options have been parsed, then getopt()
* returns -1. If getopt() encounters an option character that was not
* in optstring, then '?' is returned. If getopt() encounters an option
* with a missing argument, then the return value depends on the first
* character in optstring: if it is ':', then ':' is returned; otherwise
* '?' is returned.
*
****************************************************************************/
int getopt_common(int argc, FAR char * const argv[],
FAR const char *optstring,
FAR const struct option *longopts,
FAR int *longindex,
enum getopt_mode_e mode)
{
int ret;
/* Get thread-specific getopt() variables */
FAR struct getopt_s *go = getoptvars();
if (go == NULL)
{
return '?';
}
/* Verify input parameters. */
if (argv != NULL)
{
FAR char *optchar;
int noarg_ret = '?';
/* The initial value of optind is 1. If getopt() is called again in
* the program, optind must be reset to some value <= 1.
*/
if (go->go_optind < 1 || !go->go_binitialized)
{
go->go_optarg = NULL;
go->go_optind = 1; /* Skip over the program name */
go->go_optopt = '?';
go->go_optptr = NULL; /* Start at the beginning of the first argument */
go->go_binitialized = true; /* Now we are initialized */
}
/* Are we resuming in the middle, or at the end of a string of
* arguments? optptr == NULL means that we are started at the
* beginning of argv[optind]; *optptr == \0 means that we are
* starting at the beginning of optind+1
*/
while (!go->go_optptr || !*go->go_optptr)
{
/* We need to start at the beginning of the next argv. Check if we
* need to increment optind
*/
if (go->go_optptr)
{
/* Yes.. Increment it and check for the case where where we
* have processed everything in the argv[] array.
*/
go->go_optind++;
}
/* Check for the end of the argument list */
go->go_optptr = go->go_optind < argc ? argv[go->go_optind] : NULL;
if (!go->go_optptr)
{
/* There are no more arguments, we are finished */
go->go_binitialized = false;
return ERROR;
}
/* We are starting at the beginning of argv[optind]. In this case,
* the first character must be '-'
*/
if (*go->go_optptr != '-')
{
/* The argument does not start with '-', we are finished */
go->go_binitialized = false;
return ERROR;
}
/* Skip over the '-' */
go->go_optptr++;
}
/* Special case handling of "-" and "-:" */
if (!*go->go_optptr)
{
/* We'll fix up optptr the next time we are called */
go->go_optopt = '\0';
return '?';
}
/* Handle the case of "-:" */
if (*go->go_optptr == ':')
{
go->go_optopt = ':';
go->go_optptr++;
return '?';
}
/* go->go_optptr now points at the next option and it is not something
* crazy. Possibilities:
*
* FORM APPLICABILITY
* -o getopt(), getopt_long_only()
* -o reqarg getopt(), getopt_long_only()
* -o optarg getopt_long_only()
* -option getopt_long_only()
* -option reqarg getopt_long_only()
* -option optarg getopt_long_only()
* --option getopt_long(), getopt_long_only()
* --option reqarg getopt_long(), getopt_long_only()
* --option optarg getopt_long(), getopt_long_only()
*
* Where:
* o - Some short option
* option - Some long option
* reqarg - A required argument
* optarg - An optional argument
*/
/* Check for --option forms or -option forms */
if (GETOPT_HAVE_LONG(mode))
{
/* Handle -option and --option forms. */
if (*go->go_optptr == '-')
{
/* Skip over the second '-' */
go->go_optptr++;
/* And parse the long option */
ret = getopt_long_option(go, argv, longopts, longindex);
if (ret == '?')
{
/* Skip over the unrecognized long option. */
go->go_optind++;
go->go_optptr = NULL;
}
return ret;
}
/* The -option form is only valid in getop_long_only() mode and
* must be distinguished from the -o case forms.
*/
else if (GETOPT_HAVE_LONGONLY(mode))
{
/* A special case is that the option is of a form like
* -o but is represented as a single character long option.
* In that case, getopt_long_option() will fail with '?' and,
* if it is a single character option, we can just fall
* through to the short option logic.
*/
ret = getopt_long_option(go, argv, longopts, longindex);
if (ret != '?')
{
/* Return success or ERROR */
return ret;
}
/* Check for single character option.
*
* REVISIT: There is no way to distinguish a sequence of
* short arguments like -abc (meaning -a -b -c) from a single
* long argument (like "abc"). I am not sure of the correct
* behavior in this case. While supported for getopt(), I do
* not think that the first interpretation is standard.
*/
else if (go->go_optptr == NULL || go->go_optptr[1] != '\0')
{
/* Skip over the unrecognized long option. */
go->go_optind++;
go->go_optptr = NULL;
return ret;
}
}
}
/* Check if the option is in the list of valid short options.
* In long option modes, opstring may be NULL. However, that is
* an error in any case here because we have not found any
* long options.
*/
if (optstring == NULL)
{
/* Not an error with getopt_long() */
if (GETOPT_HAVE_LONG(mode))
{
/* Return '?'. optptr is reset to the next argv entry,
* discarding everything else that follows in the argv string
* (which could be another single character command).
*/
DEBUGASSERT(go->go_optptr != NULL);
go->go_optopt = *go->go_optptr;
go->go_optptr = NULL;
go->go_optind++;
return '?';
}
else
{
/* Restore the initial, uninitialized state, and return an
* error.
*/
go->go_binitialized = false;
return ERROR;
}
}
/* If the first character of opstring s ':', then ':' is in the event
* of a missing argument. Otherwise '?' is returned.
*/
if (*optstring == ':')
{
noarg_ret = ':';
optstring++;
}
/* Check if the option appears in 'optstring' */
DEBUGASSERT(go->go_optptr != NULL);
optchar = strchr(optstring, *go->go_optptr);
if (!optchar)
{
/* No this character is not in the list of valid options */
go->go_optopt = *go->go_optptr;
go->go_optptr++;
return '?';
}
/* Yes, the character is in the list of valid options. Does it have a
* required argument?
*/
if (optchar[1] != ':')
{
/* No, no arguments. Just return the character that we found */
go->go_optptr++;
return *optchar;
}
/* Yes, it may have an argument. Is the argument immediately after
* the command in this same argument?
*/
if (go->go_optptr[1] != '\0')
{
/* Yes, return a pointer into the current argument */
go->go_optarg = &go->go_optptr[1];
go->go_optind++;
go->go_optptr = NULL;
return *optchar;
}
/* No.. is there an argument in the next value of argv[] ? */
if (argv[go->go_optind + 1] && *argv[go->go_optind + 1] != '-')
{
/* Yes.. return that */
go->go_optarg = argv[go->go_optind + 1];
go->go_optind += 2;
go->go_optptr = NULL;
return *optchar;
}
/* No argument was supplied */
go->go_optptr = NULL;
go->go_optarg = NULL;
go->go_optopt = *optchar;
go->go_optind++;
/* Two colons means that the argument is optional. */
return (optchar[2] == ':') ? *optchar : noarg_ret;
}
/* Restore the initial, uninitialized state, and return an error. */
go->go_binitialized = false;
return ERROR;
}
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