C //练习 5-16 增加选项-d（代表目录顺序）。该选项表明，只对字母、数字和空格进行比较。要保证该选项可以和-f组合在一起使用。

本文主要是介绍C //练习 5-16 增加选项-d（代表目录顺序）。该选项表明，只对字母、数字和空格进行比较。要保证该选项可以和-f组合在一起使用。，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

C程序设计语言（第二版）练习 5-16

练习 5-16 增加选项-d（代表目录顺序）。该选项表明，只对字母、数字和空格进行比较。要保证该选项可以和-f组合在一起使用。

注意：代码在win32控制台运行，在不同的IDE环境下，有部分可能需要变更。

IDE工具：Visual Studio 2010

代码块：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>#define MAXLINES 5000char *lineptr[MAXLINES];int readlines(char *lineptr[], int nlines);
void writelines(char *lineptr[], int nlines, int reverse);
void q_sort(void *lineptr[], int left, int right, int (*comp)(void *, void *));
int numcmp(char *, char *);
int strfcmp(char *, char*);
int strdcmp(char *, char *);
int strdfcmp(char *, char *);int main(int argc, char *argv[]) {int nlines;int numeric = 0;int reverse = 0;int fold = 0;int dir = 0;while (--argc > 0 && (*++argv)[0] == '-') {int c;while (c = *++argv[0])switch (c) {case 'n':numeric = 1;break;case 'r':reverse = 1;break;case 'f':fold = 1;break;case 'd':dir = 1;break;default:printf("Illegal option: %c\n", c);break;}}if (argc != 0)printf("Usage: sort -n -r -f\n");printf(numeric ? "Numerical sort\n" : "Lexicographic sort\n");printf(reverse ? "Reverse sort\n" : "Normal sort\n");printf(fold ? "Case insensitive\n" : "Case sensitive\n");printf(dir ? "Directory order\n" : "");if ((nlines = readlines(lineptr, MAXLINES)) > 0) {if (numeric)q_sort((void **) lineptr, 0, nlines - 1,(int (*)(void *, void *)) numcmp);else if (dir)if (fold)  q_sort((void **) lineptr, 0, nlines - 1,(int (*)(void *, void *)) strdfcmp);elseq_sort((void **) lineptr, 0, nlines - 1,(int (*)(void *, void *)) strdcmp);elseif (fold)q_sort((void **) lineptr, 0, nlines - 1,(int (*)(void *, void *)) strfcmp);elseq_sort((void **) lineptr, 0, nlines - 1,(int (*)(void *, void *)) strcmp);writelines(lineptr, nlines, reverse);return 0;} else {printf("input too big to sort\n");return 1;}system("pause");return 0;
}void q_sort(void *v[], int left, int right, int (*comp)(void *, void *)) {int i, last;void swap(void *v[], int, int);if (left >= right)return;swap(v, left, (left + right) / 2);last = left;for (i = left + 1; i <= right; i++)if ((*comp)(v[i], v[left]) < 0) swap(v, ++last, i);swap(v, left, last);q_sort(v, left, last - 1, comp);q_sort(v, last + 1, right, comp);
}int strdcmp(char *s1, char *s2) {char a, b;do {while (!isalnum(*s1) && *s1 != ' ' && *s1 != '\0')s1++;while (!isalnum(*s2) && *s2 != ' ' && *s2 != '\0')s2++;a = *s1;s1++;b = *s2;s2++;if (a == b && a == '\0')return 0;} while (a == b);return a - b;}int strdfcmp(char *s1, char *s2) {char a, b;do {while (!isalnum(*s1) && *s1 != ' ' && *s1 != '\0')s1++;while (!isalnum(*s2) && *s2 != ' ' && *s2 != '\0')s2++;a = tolower(*s1);s1++;b = tolower(*s2);s2++;if (a == b && a == '\0')return 0;} while (a == b);return a - b;
}int strfcmp(char *s1, char *s2) {for ( ; tolower(*s1) == tolower(*s2); s1++, s2++)if (*s1 == '\0')return 0;return tolower(*s1)-tolower(*s2);
}int numcmp(char *s1, char *s2) {double v1, v2;v1 = atof(s1);v2 = atof(s2);if (v1 < v2)return -1;else if (v1 > v2)return 1;elsereturn 0;
}void swap(void *v[], int i, int j) {void *temp;temp = v[i];v[i] = v[j];v[j] = temp;
}#define MAXLEN 1000int get_line(char line[], int maxline);
char *alloc(int);int readlines(char *lineptr[], int maxlines) {int len, nlines;char *p, line[MAXLEN];nlines = 0;while ((len = get_line(line, MAXLEN)) > 0)if (nlines >= MAXLINES || (p = alloc(len)) == NULL)return -1;else {line[len - 1] = '\0';strcpy(p, line);lineptr[nlines++] = p;}return nlines;}void writelines(char * lineptr[], int nlines, int reverse) {int i;if (reverse)for (i = nlines-1; i >= 0; i--)printf("%s\n", lineptr[i]);elsefor (i = 0; i < nlines; i++)printf("%s\n", lineptr[i]);
}int get_line(char s[], int lim) {int c, i;for (i = 0; i < lim - 1 && (c = getchar()) != EOF && c != '\n'; ++i)s[i] = c;if (c == '\n') s[i++] = c;s[i] = '\0';return i;
}#define ALLOCSIZE 10000static char allocbuf[ALLOCSIZE];
static char *allocp = allocbuf;char *alloc(int n) {if (allocbuf + ALLOCSIZE - allocp >= n) {allocp += n;return allocp - n;} elsereturn 0;
}void afree(char *p) {if (p >= allocbuf && p < allocbuf + ALLOCSIZE)allocp = p;
}