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Groups > comp.lang.c > #162511
| From | Bonita Montero <Bonita.Montero@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Freeing a dynamically allocated array of structs within a struct in C |
| Date | 2021-08-31 10:59 +0200 |
| Organization | A noiseless patient Spider |
| Message-ID | <sgkr22$ida$1@dont-email.me> (permalink) |
| References | <1348a974-54cd-47cf-bf40-7034feaa1f78n@googlegroups.com> <sggi2c$jkm$1@dont-email.me> <sghvo3$jra$1@dont-email.me> <20210831003134.197@kylheku.com> |
Am 31.08.2021 um 09:50 schrieb Kaz Kylheku:
> On 2021-08-30, Bonita Montero <Bonita.Montero@gmail.com> wrote:
>> Am 29.08.2021 um 20:01 schrieb Bonita Montero:
>>> Use a proper language:
>>>
>>> #include <memory>
>>> #include <string>
>>>
>>> using namespace std;
>>>
>>> struct deck_entry
>>> {
>>> string key,
>>> value;
>>> };
>>>
>>> using up_de_t = unique_ptr<deck_entry>;
>>>
>>> up_de_t parse_deck_entry( string const &parse )
>>> {
>>> size_t delimiterBegin = parse.find( ": " );
>>> if( delimiterBegin == string::npos )
>>> return up_de_t();
>>> up_de_t de = make_unique<deck_entry>();
>>> de->key = string( parse.begin(), parse.begin() + delimiterBegin );
>>> de->value = string( parse.begin() + (delimiterBegin + 2),
>>> parse.end() );
>>> return de;
>>> }
>>
>> And now this ugly C-pendant:
>>
>> #include <stddef.h>
>> #include <string.h>
>> #include <stdlib.h>
>>
>> typedef struct deck_entry
>> {
>> char *key,
>> *value;
>> } deck_entry;
>>
>> deck_entry *parseDeckEntry( char const *parse )
>> {
>> size_t len = strlen( parse );
>> char const *delimiter = strstr( parse, ": " );
>> if( !delimiter || delimiter == parse || delimiter == parse + len - 2 )
>> return NULL;
>> deck_entry *de = NULL;
>> if( !(de = malloc( sizeof(deck_entry) )) )
>> return NULL;
>> char *key, *value;
>> if( !(de->key = malloc( delimiter - parse + 1 )) )
>> goto undoDE;
>> if( !(de->value = malloc( len - (delimiter - parse + 2) + 1 )) )
>> goto undoKey;
>> strncpy( de->key, parse, delimiter - parse );
>> strcpy( de->value, delimiter + 2 );
>> return de;
>> undoKey:
>> free( de->key );
>> undoDE:
>> free( de );
>> return NULL;
>> }
>
> That's fine, but when you're dealing with manual resource management,
> a structure like the following structure is nice:
>
> deck_entry *parseDeckEntry(char const *parse)
> {
> size_t len = strlen(parse);
> char const *delimiter = strstr(parse, ": ");
>
> if (!delimiter || delimiter == parse || delimiter == parse + len - 2)
> return NULL;
>
> deck_entry *de = malloc(sizeof *de);
> char *key = malloc(delimiter - parse + 1);
> char *value = malloc(len - (delimiter - parse + 2) + 1);
>
> if (de && key && value) {
> strncpy(key, parse, delimiter - parse);
> strcpy(value, delimiter + 2);
> de->key = key;
> de->value = value;
> return de;
> }
>
> free(value);
> free(key);
> free(de);
>
> return NULL;
> }
> }
I "prefer" the goto-way like the people in the Linux-kernel do.
It only deallocates the resources already allocated.
But nevertheless programming this with manual resource management
is a mess.
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Freeing a dynamically allocated array of structs within a struct in C Bithov Vinu Student <vinub@calday.co.uk> - 2021-08-29 08:34 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-29 15:43 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-29 16:12 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-09-06 05:46 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-08-29 17:17 +0100
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-29 20:01 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-29 18:21 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-29 20:34 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-30 09:01 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Robert Latest <boblatest@yahoo.com> - 2021-08-31 05:44 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Kaz Kylheku <563-365-8930@kylheku.com> - 2021-08-31 07:50 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-31 10:59 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-30 09:45 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-30 10:15 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Kaz Kylheku <563-365-8930@kylheku.com> - 2021-08-29 18:14 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-29 18:18 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Barry Schwarz <schwarzb@delq.com> - 2021-08-29 11:44 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-29 19:04 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Barry Schwarz <schwarzb@delq.com> - 2021-08-29 14:15 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C scott@slp53.sl.home (Scott Lurndal) - 2021-08-29 21:19 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Barry Schwarz <schwarzb@delq.com> - 2021-08-29 18:14 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-30 18:27 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-30 16:17 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-08-30 14:14 -0400
Re: Freeing a dynamically allocated array of structs within a struct in C Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-08-30 11:39 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-08-31 10:08 -0400
Re: Freeing a dynamically allocated array of structs within a struct in C Kaz Kylheku <563-365-8930@kylheku.com> - 2021-09-01 04:40 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-01 00:57 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-30 19:16 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Manfred <noname@add.invalid> - 2021-08-30 21:49 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-08-30 12:49 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C scott@slp53.sl.home (Scott Lurndal) - 2021-08-30 22:31 +0000
Re: Freeing a dynamically allocated array of structs within a struct in C Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-09-30 07:04 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-08-29 15:38 -0700
Re: Freeing a dynamically allocated array of structs within a struct in C Manfred <noname@add.invalid> - 2021-08-30 14:21 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-30 18:29 +0200
Re: Freeing a dynamically allocated array of structs within a struct in C Bart <bc@freeuk.com> - 2021-08-30 18:30 +0100
Re: Freeing a dynamically allocated array of structs within a struct in C Bonita Montero <Bonita.Montero@gmail.com> - 2021-08-31 04:22 +0200
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