ls.c (2507B)
1 /* $Id: //depot/blt/bin/ls/ls.c#4 $ 2 ** 3 ** Copyright 1999 Sidney Cammeresi 4 ** All rights reserved. 5 ** 6 ** Redistribution and use in source and binary forms, with or without 7 ** modification, are permitted provided that the following conditions 8 ** are met: 9 ** 1. Redistributions of source code must retain the above copyright 10 ** notice, this list of conditions, and the following disclaimer. 11 ** 2. Redistributions in binary form must reproduce the above copyright 12 ** notice, this list of conditions, and the following disclaimer in the 13 ** documentation and/or other materials provided with the distribution. 14 ** 3. The name of the author may not be used to endorse or promote products 15 ** derived from this software without specific prior written permission. 16 ** 17 ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 ** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 ** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 ** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 ** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 ** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <dirent.h> 33 34 static int dirent_compare (const void *a, const void *b) 35 { 36 const struct dirent *c, *d; 37 38 c = a, d = b; 39 return strcmp (c->d_name, d->d_name); 40 } 41 42 int main (int argc, char **argv) 43 { 44 char *path; 45 int i, j, k, l, maxlen, maxnum; 46 struct dirent *ent[128]; 47 DIR *dir; 48 49 path = (argc == 1) ? "/" : argv[1]; 50 i = maxlen = 0; 51 dir = opendir (path); 52 if (dir == NULL) 53 { 54 printf ("ls: %s: no such file or directory\n", path); 55 return 0; 56 } 57 while ((ent[i] = readdir (dir)) != NULL) 58 { 59 maxlen = (strlen (ent[i]->d_name) > maxlen) ? strlen (ent[i]->d_name) : 60 maxlen; 61 i++; 62 } 63 closedir (dir); 64 maxnum = 80 / (maxlen + 2); 65 qsort (*ent, i, sizeof (struct dirent), dirent_compare); 66 for (k = 0; k < i; k+= j) 67 { 68 for (j = 0; ((j + k) < i) && (j < maxnum); j++) 69 { 70 printf ("%s", ent[j + k]->d_name); 71 for (l = strlen (ent[j + k]->d_name); l < (maxlen + 2); l++) 72 printf (" "); 73 } 74 printf ("\n"); 75 } 76 77 return 0; 78 } 79