diff options
Diffstat (limited to 'sort.c')
| -rw-r--r-- | sort.c | 93 |
1 files changed, 72 insertions, 21 deletions
@@ -32,23 +32,26 @@ static const char sort_usage[] = "Usage: sort [OPTION]... [FILE]...\n\n" ; -/* structs ________________________________________________________________ */ +/* typedefs _______________________________________________________________ */ /* line node */ -typedef struct { - char *data; /* line data */ - struct Line *next; /* pointer to next line node */ +typedef struct Line { + char *data; /* line data */ + struct Line *next; /* pointer to next line node */ } Line; /* singly-linked list of lines */ typedef struct { - int len; /* number of Lines */ - Line *sorted; /* array fed to qsort */ + int len; /* number of Lines */ + Line **sorted; /* array fed to qsort */ - Line *head; /* head of List */ - Line *current /* current Line */ + Line *head; /* head of List */ + Line *current; /* current Line */ } List; +/* comparison function */ +typedef int (Compare)(const void *, const void *); + /* methods ________________________________________________________________ */ @@ -105,10 +108,16 @@ line_release(Line *self) /* Comparison */ static int -compare_ascii(const void *, const void *); +compare_ascii(const void *a, const void *b) +{ + return 0; +} static int -compare_numeric(const void *, const void *); +compare_numeric(const void *a, const void *b) +{ + return 0; +} /* List */ @@ -125,7 +134,7 @@ list_init(List *self) } /* for simplicity, the List gains ownership of the line */ -static void +static List * list_insert(List *self, Line *line) { if (line == NULL) { return NULL; } @@ -137,26 +146,54 @@ list_insert(List *self, Line *line) /* all subsequent insertions */ } else { - self->current->next = line; + /* <?> the following cast shouldn't be necessary */ + self->current->next = line; self->current = line; } self->len++; return self; } -/* */ +/* order the list according to compare() */ static List * -list_sort(List *self); +list_sort(List *self, Compare *compare) +{ + int i; + Line *line; + + /* mallocate array of Line*s */ + self->sorted = (Line **) malloc(self->len * sizeof(Line*)); + if (self->sorted == NULL) { return NULL; } + + /* fill array w/ List's contents */ + i = 0; + line = self->head; + while (line) { + self->sorted[i++] = line; + line = line->next; + } + + /* apply qsort */ + qsort(self->sorted, sizeof(Line*), self->len, compare); + return self; +} /* precondition: list must be sorted */ static List * list_writeToFile(List *self, FILE* dst) { + int i; + Line **line = self->sorted; + if (self->sorted == NULL) { return NULL; } + for (i = 0; i < self->len; i++) { + fprintf(dst, "%s", line[i]->data); + } + return self; } /* deallocate */ -static List * +static void list_release(List *self) { Line *i; @@ -166,9 +203,8 @@ list_release(List *self) while (i) { die = i; i = die->next; - line_delete(die); + line_release(die); } - return self; /* bad poetry? */ } @@ -182,8 +218,10 @@ list_release(List *self) int sort_main(int argc, char **argv) { - int i; - char opt; + int i; + char opt; + List list; + Line *l; /* default behaviour */ @@ -204,9 +242,17 @@ sort_main(int argc, char **argv) } } + /* initialize list */ + list_init(&list); + /* go through remaining args (if any) */ if (i >= argc) { - + while ( (l = line_newFromFile(stdin))) { + list_insert(&list, l); + } + list_sort(&list, compare_ascii); + list_writeToFile(&list, stdout); + list_release(&list); } else { for ( ; i < argc; i++) { } @@ -215,4 +261,9 @@ sort_main(int argc, char **argv) exit(0); } -/* $Id: sort.c,v 1.3 1999/12/22 17:57:31 beppu Exp $ */ +/* $Id: sort.c,v 1.4 1999/12/22 22:24:52 beppu Exp $ */ +/* $Log: sort.c,v $ + * Revision 1.4 1999/12/22 22:24:52 beppu + * the base is nearly done. + * need to implement various comparison functions, now. + * */ |