/*
- * Mini find implementation for busybox
+ * Mini sort implementation for busybox
*
*
* Copyright (C) 1999 by Lineo, inc.
"Usage: sort [OPTION]... [FILE]...\n\n"
;
+/* 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 *line; /* array fed to qsort */
- Line *head; /* head of List */
+ int len; /* number of Lines */
+ Line **sorted; /* array fed to qsort */
+
+ Line *head; /* head of List */
+ Line *current; /* current Line */
} List;
+/* comparison function */
+typedef int (Compare)(const void *, const void *);
-/* Line methods */
+
+/* methods ________________________________________________________________ */
static const int max = 1024;
+/* mallocate Line */
+static Line *
+line_alloc()
+{
+ Line *self;
+ self = malloc(1 * sizeof(Line));
+ return self;
+}
+
+/* Initialize Line with string */
static Line *
-line_new()
+line_init(Line *self, const char *string)
{
- char buffer[max];
+ self->data = malloc((strlen(string) + 1) * sizeof(char));
+ if (self->data == NULL) { return NULL; }
+ strcpy(self->data, string);
+ self->next = NULL;
+ return self;
+}
+
+/* Construct Line from FILE* */
+static Line *
+line_newFromFile(FILE *src)
+{
+ char buffer[max];
+ Line *self;
+
+ if (fgets(buffer, max, src)) {
+ self = line_alloc();
+ if (self == NULL) { return NULL; }
+ line_init(self, buffer);
+ return self;
+ }
+ return NULL;
+}
+
+/* Line destructor */
+static Line *
+line_release(Line *self)
+{
+ if (self->data) {
+ free(self->data);
+ free(self);
+ }
+ return self;
}
/* Comparison */
+/* ascii order */
static int
-compare_ascii(const void *, const void *);
+compare_ascii(const void *a, const void *b)
+{
+ Line **doh;
+ Line *x, *y;
+
+ doh = (Line **) a;
+ x = *doh;
+ doh = (Line **) b;
+ y = *doh;
+ // fprintf(stdout, "> %p: %s< %p: %s", x, x->data, y, y->data);
+ return strcmp(x->data, y->data);
+}
+
+/* numeric order */
static int
-compare_numeric(const void *, const void *);
+compare_numeric(const void *a, const void *b)
+{
+ Line **doh;
+ Line *x, *y;
+ int xint, yint;
+
+ doh = (Line **) a;
+ x = *doh;
+ doh = (Line **) b;
+ y = *doh;
+
+ xint = strtoul(x->data, NULL, 10);
+ yint = strtoul(y->data, NULL, 10);
+
+ return (xint - yint);
+}
/* List */
-static void
-list_insert();
+/* */
+static List *
+list_init(List *self)
+{
+ self->len = 0;
+ self->sorted = NULL;
+ self->head = NULL;
+ self->current = NULL;
+ return self;
+}
-static void
-list_sort();
+/* for simplicity, the List gains ownership of the line */
+static List *
+list_insert(List *self, Line *line)
+{
+ if (line == NULL) { return NULL; }
+
+ /* first insertion */
+ if (self->head == NULL) {
+ self->head = line;
+ self->current = line;
+
+ /* all subsequent insertions */
+ } else {
+ self->current->next = line;
+ self->current = line;
+ }
+ self->len++;
+ return self;
+}
+
+/* order the list according to compare() */
+static List *
+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, self->len, sizeof(Line*), 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 void
-list_print();
+list_release(List *self)
+{
+ Line *i;
+ Line *die;
+ i = self->head;
+ while (i) {
+ die = i;
+ i = die->next;
+ line_release(die);
+ }
+}
/*
int
sort_main(int argc, char **argv)
{
- int i;
- char opt;
+ int i;
+ char opt;
+ List list;
+ Line *l;
+ Compare *compare;
- /* default behaviour */
+ /* init */
+ compare = compare_ascii;
+ list_init(&list);
/* parse argv[] */
for (i = 1; i < argc; i++) {
if (argv[i][0] == '-') {
opt = argv[i][1];
switch (opt) {
+ case 'g':
+ /* what's the diff between -g && -n? */
+ compare = compare_numeric;
+ break;
case 'h':
usage(sort_usage);
break;
+ case 'n':
+ /* what's the diff between -g && -n? */
+ compare = compare_numeric;
+ break;
+ case 'r':
+ /* reverse */
+ break;
default:
fprintf(stderr, "sort: invalid option -- %c\n", opt);
usage(sort_usage);
}
}
- /* go through remaining args (if any) */
+ /* this could be factored better */
+
+ /* work w/ stdin */
if (i >= argc) {
+ while ( (l = line_newFromFile(stdin))) {
+ list_insert(&list, l);
+ }
+ list_sort(&list, compare);
+ list_writeToFile(&list, stdout);
+ list_release(&list);
+ /* work w/ what's left in argv[] */
} else {
+ FILE *src;
+
for ( ; i < argc; i++) {
+ src = fopen(argv[i], "r");
+ if (src == NULL) { break; }
+ while ( (l = line_newFromFile(src))) {
+ list_insert(&list, l);
+ }
+ fclose(src);
}
+ list_sort(&list, compare);
+ list_writeToFile(&list, stdout);
+ list_release(&list);
}
exit(0);
}
-/* $Date: 1999/12/21 20:00:35 $ */
-/* $Id: sort.c,v 1.1 1999/12/21 20:00:35 beppu Exp $ */
+/* $Id: sort.c,v 1.8 1999/12/23 22:46:10 beppu Exp $ */
projects / oweals / busybox.git / blobdiff