#include
#include
#define NUMERIC 1
#define DECR 2
#define FOLD 4
#define DIR 8
#define MAXLINES 5000
#define MAXLEN 1000
#define MAXSTORAGE 10000
char *lineptr[MAXLINES];
char lines[MAXSTORAGE];
int charcmp(char *, char *);
void error(char *);
int numcmp(char *, char *);
void readargs(int argc, char *argv[]);
int p_readlines(char *lineptr[], int maxlines);
void p_qsort(void *v[], int left, int right, int (*comp)(void *, void *));
void writelines(char *lineptr[], int nlines, int order);
char option = 0;
int pos1 = 0;
int pos2 = 0;
int main(int argc, char *argv[])
{
int nlines;
int rc = 0;
readargs(argc, argv);
if ((nlines = p_readlines(lineptr, MAXLINES)) > 0) {
if (option & NUMERIC)
p_qsort((void **)lineptr, 0, nlines-1, (int (*)(void *, void *))numcmp);
else
p_qsort((void **)lineptr, 0, nlines-1, (int (*)(void *, void *))charcmp);
writelines(lineptr, nlines, option & DECR);
} else {
printf("input too big to sort!\n");
rc = -1;
}
system("pause");
return rc;
}
void readargs(int argc, char *argv[])
{
int c;
while (--argc > 0 && (c = (*++argv)[0]) == '-' || c == '+') {
if (c == '-' && !isdigit(*(argv[0]+1)))
{
while (c = *++argv[0])
{
switch(c) {
case 'd':
option |= DIR;
break;
case 'f':
option |= FOLD;
break;
case 'n':
option |= NUMERIC;
break;
case 'r':
option |= DECR;
break;
default:
printf("sort: illegal option %c\n", c);
error("Usage: sort -dfnr [+pos1] [-pos2]");
break;
}
}
} else if (c == '-') {
pos2 = atoi(argv[0]+1);
} else if ((pos1 = atoi(argv[0]+1)) < 0)
error("Usage: sort -dfnr [+pos1] [-pos2]");
}
if (argc || pos1 > pos2)
error("Usage: sort -dfnr [+pos1] [-pos2]");
}
int p_readlines(char *lineptr[], int maxlines)
{
int len, nlines;
char *p = lines, line[MAXLEN];
nlines = 0;
printf("Please input a string(# to end input): ");
while ((len = getline(line, MAXLEN)) > 0)
{
if (strcmp(line, "#\n") == 0)
break;
if (nlines >= maxlines || p + len >= lines + MAXSTORAGE)
return -1;
else {
line[len - 1] = '\0';
strcpy(p, line);
lineptr[nlines++] = p;
p += len;
}
printf("Please input a string(# to end input): ");
}
return nlines;
}
void writelines(char *lineptr[], int nlines, int order)
{
int i;
if (order)
for (i = nlines -1; i >= 0; i--)
printf("%s\n", lineptr[i]);
else
for (i = 0; i < nlines; i++)
printf("%s\n", lineptr[i]);
printf("\n");
}
void swap(void *v[], int i, int j)
{
void *temp;
temp = v[i];
v[i] = v[j];
v[j] = temp;
}
int getline(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;
++i;
}
s[i] = '\0';
return i;
}
void p_qsort(void *v[], int left, int right, int(*comp)(void *, void *))
{
int i, last;
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);
p_qsort(v, left, last - 1, comp);
p_qsort(v, last + 1, right, comp);
}
void error(char *s)
{
printf("%s\n", s);
exit(1);
}