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/*
cl /AL sortit.c
===========================================================
sort.c 7-31-91 Robert Mashlan
This filter is almost compatible with the MS-DOS filter of the same name.
This filter sorts each line of standard input, disregarding case,
and sends it to standard output.
optional parameters: /R Output in reverse order
/+n Compare at column n, 1 based
example usage: sort < unsorted.txt > sorted.txt
note: compile in a far data model for maximum capacity ( compact or large )
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define MAXLINES 10000 /* maximum number of lines to sort */
#define MAXLINE 80 /* maximum line length */
unsigned col = 0; /* column to start sort at ( zero based here ) */
int reverse = 0; /* reverse order flag */
/*
** compare function for qsort
*/
int cmp( const void *a, const void *b)
{
int result;
const char *_a = *(const char **)a;
const char *_b = *(const char **)b;
/* compare at col if other than zero */
if (col > 0)
{
if (strlen(_a) > col)
_a += col;
else _a = "";
if (strlen(_b) > col)
_b += col;
else _b = "";
}
result = stricmp(_a,_b);
return reverse ? -result : result;
}
int main(int argc, char *argv[])
{
static char *lines[MAXLINES];
int i, nlines=0, no_match;
char buf[MAXLINE];
/* scan for command line options */
for(i=1;i<argc;i++)
{
if(!stricmp(argv[i],"/R")) /* reverse order option */
reverse=1;
else if (!strnicmp(argv[i],"/+",2)) /* column number option */
{
col=atoi(argv[i]+1)-1;
if (col<0)
col=0;
}
else
{
fputs("Invalid Parameter",stderr);
return 1;
}
}
while(1)
{
/* read the line */
if(fgets(buf,MAXLINE,stdin)==NULL)
break;
/* Check for duplicates here */
no_match = 1;
for ( i=0; i< nlines; i++ )
{
if (0 == (no_match = memicmp(buf, lines[i],
(unsigned int)12)))
{
break;
}
}
if (no_match) /* make a duplicate on the heap */
{
if((lines[nlines++]=strdup(buf))==NULL)
{
fputs("SORT: Insufficent memory",stderr);
return 2;
}
}
}
/* sort the lot */
qsort((void *)lines,nlines,sizeof(char *),cmp);
/* display the sorted output */
for (i=0;i<nlines;i++)
fputs(lines[i],stdout); /* send it to standard output */
return 0;
}
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