sys/src/cmd/news.c

   1 /*
   2  *      news foo        prints /lib/news/foo
   3  *      news -a         prints all news items, latest first
   4  *      news -n         lists names of new items
   5  *      news            prints items changed since last news
   6  */
   7
   8 #include <u.h>
   9 #include <libc.h>
  10 #include <bio.h>
  11
  12 #define NINC    50      /* Multiples of directory allocation */
  13 char    NEWS[] = "/lib/news";
  14 char    TFILE[] = "%s/lib/newstime";
  15
  16 /*
  17  *      The following items should not be printed.
  18  */
  19 char*   ignore[] =
  20 {
  21         "core",
  22         "dead.letter",
  23         0
  24 };
  25
  26 typedef
  27 struct
  28 {
  29         long    time;
  30         char    *name;
  31         vlong   length;
  32 } File;
  33 File*   n_list;
  34 int     n_count;
  35 int     n_items;
  36 Biobuf  bout;
  37
  38 int     fcmp(void *a, void *b);
  39 void    read_dir(int update);
  40 void    print_item(char *f);
  41 void    eachitem(void (*emit)(char*), int all, int update);
  42 void    note(char *s);
  43
  44 void
  45 main(int argc, char *argv[])
  46 {
  47         int i;
  48
  49         Binit(&bout, 1, OWRITE);
  50         if(argc == 1) {
  51                 eachitem(print_item, 0, 1);
  52                 exits(0);
  53         }
  54         ARGBEGIN{
  55         case 'a':       /* print all */
  56                 eachitem(print_item, 1, 0);
  57                 break;
  58
  59         case 'n':       /* names only */
  60                 eachitem(note, 0, 0);
  61                 if(n_items)
  62                         Bputc(&bout, '\n');
  63                 break;
  64
  65         default:
  66                 fprint(2, "news: bad option %c\n", ARGC());
  67                 exits("usage");
  68         }ARGEND
  69         for(i=0; i<argc; i++)
  70                 print_item(argv[i]);
  71         exits(0);
  72 }
  73
  74 int
  75 fcmp(void *a, void *b)
  76 {
  77         long x;
  78
  79         x = ((File*)b)->time - ((File*)a)->time;
  80         if(x < 0)
  81                 return -1;
  82         if(x > 0)
  83                 return 1;
  84         return 0;
  85 }
  86
  87 /*
  88  *      read_dir: get the file names and modification dates for the
  89  *      files in /usr/news into n_list; sort them in reverse by
  90  *      modification date.
  91  */
  92 void
  93 read_dir(int update)
  94 {
  95         Dir *d;
  96         char newstime[100], *home;
  97         int i, j, n, na, fd;
  98
  99         n_count = 0;
 100         n_list = malloc(NINC*sizeof(File));
 101         na = NINC;
 102         home = getenv("home");
 103         if(home) {
 104                 sprint(newstime, TFILE, home);
 105                 d = dirstat(newstime);
 106                 if(d != nil) {
 107                         n_list[n_count].name = strdup("");
 108                         n_list[n_count].time =d->mtime-1;
 109                         n_list[n_count].length = 0;
 110                         n_count++;
 111                         free(d);
 112                 }
 113                 if(update) {
 114                         fd = create(newstime, OWRITE, 0644);
 115                         if(fd >= 0)
 116                                 close(fd);
 117                 }
 118         }
 119         fd = open(NEWS, OREAD);
 120         if(fd < 0) {
 121                 fprint(2, "news: ");
 122                 perror(NEWS);
 123                 exits(NEWS);
 124         }
 125
 126         n = dirreadall(fd, &d);
 127         for(i=0; i<n; i++) {
 128                 for(j=0; ignore[j]; j++)
 129                         if(strcmp(ignore[j], d[i].name) == 0)
 130                                 goto ign;
 131                 if(na <= n_count) {
 132                         na += NINC;
 133                         n_list = realloc(n_list, na*sizeof(File));
 134                 }
 135                 n_list[n_count].name = strdup(d[i].name);
 136                 n_list[n_count].time = d[i].mtime;
 137                 n_list[n_count].length = d[i].length;
 138                 n_count++;
 139         ign:;
 140         }
 141         free(d);
 142
 143         close(fd);
 144         qsort(n_list, n_count, sizeof(File), fcmp);
 145 }
 146
 147 void
 148 print_item(char *file)
 149 {
 150         char name[4096], *p, *ep;
 151         Dir *dbuf;
 152         int f, c;
 153         int bol, bop;
 154
 155         sprint(name, "%s/%s", NEWS, file);
 156         f = open(name, OREAD);
 157         if(f < 0) {
 158                 fprint(2, "news: ");
 159                 perror(name);
 160                 return;
 161         }
 162         strcpy(name, "...");
 163         dbuf = dirfstat(f);
 164         if(dbuf == nil)
 165                 return;
 166         Bprint(&bout, "\n%s (%s) %s\n", file,
 167                 dbuf->muid[0]? dbuf->muid : dbuf->uid,
 168                 asctime(localtime(dbuf->mtime)));
 169         free(dbuf);
 170
 171         bol = 1;        /* beginning of line ...\n */
 172         bop = 1;        /* beginning of page ...\n\n */
 173         for(;;) {
 174                 c = read(f, name, sizeof(name));
 175                 if(c <= 0)
 176                         break;
 177                 p = name;
 178                 ep = p+c;
 179                 while(p < ep) {
 180                         c = *p++;
 181                         if(c == '\n') {
 182                                 if(!bop) {
 183                                         Bputc(&bout, c);
 184                                         if(bol)
 185                                                 bop = 1;
 186                                         bol = 1;
 187                                 }
 188                                 continue;
 189                         }
 190                         if(bol) {
 191                                 Bputc(&bout, '\t');
 192                                 bol = 0;
 193                                 bop = 0;
 194                         }
 195                         Bputc(&bout, c);
 196                 }
 197         }
 198         if(!bol)
 199                 Bputc(&bout, '\n');
 200         close(f);
 201 }
 202
 203 void
 204 eachitem(void (*emit)(char*), int all, int update)
 205 {
 206         int i;
 207
 208         read_dir(update);
 209         for(i=0; i<n_count; i++) {
 210                 if(n_list[i].name[0] == 0) {    /* newstime */
 211                         if(all)
 212                                 continue;
 213                         break;
 214                 }
 215                 if(n_list[i].length == 0)               /* in progress */
 216                         continue;
 217                 (*emit)(n_list[i].name);
 218         }
 219 }
 220
 221 void
 222 note(char *file)
 223 {
 224
 225         if(!n_items)
 226                 Bprint(&bout, "news:");
 227         Bprint(&bout, " %s", file);
 228         n_items++;
 229 }