ACE
6.1.6
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This ADT operates on a specified set of arguments (argv). As known arguments are scanned, they are shifted to the back of the argv vector, so deeper levels of argument parsing can locate the yet unprocessed arguments at the beginning of the vector. More...
#include <Arg_Shifter.h>
Public Member Functions | |
ACE_Arg_Shifter_T (int &argc, const CHAR_TYPE **argv, const CHAR_TYPE **temp=0) | |
ACE_Arg_Shifter_T (int &argc, CHAR_TYPE **argv, CHAR_TYPE **temp=0) | |
~ACE_Arg_Shifter_T (void) | |
Destructor. | |
const CHAR_TYPE * | get_current (void) const |
Get the current head of the vector. | |
const CHAR_TYPE * | get_the_parameter (const CHAR_TYPE *flag) |
int | cur_arg_strncasecmp (const CHAR_TYPE *flag) |
int | consume_arg (int number=1) |
int | ignore_arg (int number=1) |
int | is_anything_left (void) const |
Returns the number of args left to see in the vector. | |
int | is_option_next (void) const |
int | is_parameter_next (void) const |
int | num_ignored_args (void) const |
Returns the number of irrelevant args seen. |
Private Member Functions | |
ACE_Arg_Shifter_T (const ACE_Arg_Shifter_T< CHAR_TYPE > &) | |
Copy Constructor should not be used. | |
ACE_Arg_Shifter_T | operator= (const ACE_Arg_Shifter_T< CHAR_TYPE > &) |
Assignment '=' operator should not be used. | |
void | init (void) |
Refactor the constructor logic. |
Private Attributes | |
int & | argc_ |
The size of the argument vector. | |
int | total_size_ |
The size of argv_. | |
const CHAR_TYPE ** | temp_ |
The temporary array over which we traverse. | |
const CHAR_TYPE ** | argv_ |
The array in which the arguments are reordered. | |
int | current_index_ |
The element in <temp_> we're currently examining. | |
int | back_ |
int | front_ |
This ADT operates on a specified set of arguments (argv). As known arguments are scanned, they are shifted to the back of the argv vector, so deeper levels of argument parsing can locate the yet unprocessed arguments at the beginning of the vector.
Nomenclature: argument - a member of the argv array option - an argument starting with '-' flag - synonym for "option" parameter value - an argument not starting with '-' parameter - synonym for "parameter value"
The ACE_Arg_Shifter
copies the pointers of the argv vector into a temporary array, emptying the original. As the ACE_Arg_Shifter
iterates over the temporary array, it places known arguments in the rear of the original array and places the unknown ones in the beginning of the original array. It modifies argc to be the number of unknown arguments, so it looks to the caller as if the original array contains only unknown arguments. So, after ACE_Arg_Shifter
has visited all the arguments in the temporary array, the original argv array appears to contain only the unknown arguments in their original order (but it actually has all the known arguments, too, beyond argc).
ACE_Arg_Shifter_T< CHAR_TYPE >::ACE_Arg_Shifter_T | ( | int & | argc, |
const CHAR_TYPE ** | argv, | ||
const CHAR_TYPE ** | temp = 0 |
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Initialize the ACE_Arg_Shifter to the vector over which to iterate. Optionally, also provide the temporary array for use in shifting the arguments. If ACE_Arg_Shifter must allocate the temporary vector internally and dynamic allocation fails, the ACE_Arg_Shifter will set all indicators to end of the vector, forbidding iteration. Following iteration over argv, the argc value will be updated to contain the number of unconsumed arguments.
argc | The number of strings in argv. argc will be updated to reflect the number of unconsumed arguments. |
argv | The argument vector to shift. The string pointers in the vector will be reordered to place the argc unconsumed arguments at the front of the vector. |
temp | A vector of CHAR_TYPE pointers at least argc elements long. The vector will be used for argument shifting as the specified argv vector is consumed. The vector must not be modified while this object exists. If this argument is 0 (the default) the object will allocate and free the temporary vector transparently. |
ACE_Arg_Shifter_T< CHAR_TYPE >::ACE_Arg_Shifter_T | ( | int & | argc, |
CHAR_TYPE ** | argv, | ||
CHAR_TYPE ** | temp = 0 |
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) |
Same behavior as the preceding constructor, but without the "const" qualifier.
ACE_Arg_Shifter_T< CHAR_TYPE >::~ACE_Arg_Shifter_T | ( | void | ) |
Destructor.
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private |
Copy Constructor should not be used.
int ACE_Arg_Shifter_T< CHAR_TYPE >::consume_arg | ( | int | number = 1 | ) |
Consume number argument(s) by sticking them/it on the end of the vector.
int ACE_Arg_Shifter_T< CHAR_TYPE >::cur_arg_strncasecmp | ( | const CHAR_TYPE * | flag | ) |
Check if the current argument matches (case insensitive) flag
Case A: Perfect Match (case insensitive) 0 is returned.
ie: when current_arg = "-foobar" or "-FOOBAR" or "-fooBAR" this->cur_arg_strncasecmp ("-FooBar); will return 0
Case B: Perfect Match (case insensitive) but the current_arg is longer than the flag. Returns a number equal to the index in the char* indicating the start of the extra characters
ie: when current_arg = "-foobar98023" this->cur_arg_strncasecmp ("-FooBar); will return 7
Notice: this number will always be > 0
Case C: If neither of Case A or B is met (no match) then -1 is returned
const CHAR_TYPE * ACE_Arg_Shifter_T< CHAR_TYPE >::get_current | ( | void | ) | const |
Get the current head of the vector.
const CHAR_TYPE * ACE_Arg_Shifter_T< CHAR_TYPE >::get_the_parameter | ( | const CHAR_TYPE * | flag | ) |
If the flag matches the current_arg of arg shifter this method will attempt to return the associated parameter value
Safe to call without checking that a current arg exists
In the following examples, a pointer to the char* "value" is ret
eg: main -foobar value, main -FooBar value main -FOOBARvalue
all of the above will all match the flag == -FooBar and will return a char* to "value"
main -foobar 4 would succeed and return a char* to "4" main -foobar -4 does not succeed (-4 is not a parameter) but instead, would return 0
0 is returned: If the current argument does not match flag If there is no parameter found after a 'matched' flag
If the flag is matched and the flag and parameter DO NOT RUN together, the flag is consumed, the parameter is returned, and the new current argument is the parameter value. ie '-foobarflag VALUE' leaves the new cur arg == "VALUE"
If the flag is matched and the flag and parameter RUN together '-foobarflagVALUE', the flag is NOT consumed and the cur arg is left pointing to the entire flag/value pair
int ACE_Arg_Shifter_T< CHAR_TYPE >::ignore_arg | ( | int | number = 1 | ) |
Place number arguments in the same relative order ahead of the known arguments in the vector.
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private |
Refactor the constructor logic.
int ACE_Arg_Shifter_T< CHAR_TYPE >::is_anything_left | ( | void | ) | const |
Returns the number of args left to see in the vector.
int ACE_Arg_Shifter_T< CHAR_TYPE >::is_option_next | ( | void | ) | const |
Returns 1 if there's a next item in the vector and it begins with '-'.
int ACE_Arg_Shifter_T< CHAR_TYPE >::is_parameter_next | ( | void | ) | const |
Returns 1 if there's a next item in the vector and it doesn't begin with '-'.
int ACE_Arg_Shifter_T< CHAR_TYPE >::num_ignored_args | ( | void | ) | const |
Returns the number of irrelevant args seen.
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Assignment '=' operator should not be used.
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The size of the argument vector.
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The array in which the arguments are reordered.
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The index of <argv_> in which we'll stick the next unknown argument.
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The element in <temp_> we're currently examining.
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The index of <argv_> in which we'll stick the next known argument. This is not really the "front" at all. It's the point after which the unknown arguments end and at which the known arguments begin.
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The temporary array over which we traverse.
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The size of argv_.