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      1 /* paste.c - Merge corresponding lines
      2  *
      3  * Copyright 2012 Felix Janda <felix.janda (at) posteo.de>
      4  *
      5  * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/paste.html
      6  *
      7  * Deviations from posix: the FILE argument isn't mandatory, none == '-'
      8 
      9 USE_PASTE(NEWTOY(paste, "d:s", TOYFLAG_BIN|TOYFLAG_LOCALE))
     10 
     11 config PASTE
     12   bool "paste"
     13   default y
     14   help
     15     usage: paste [-s] [-d DELIMITERS] [FILE...]
     16 
     17     Merge corresponding lines from each input file.
     18 
     19     -d	list of delimiter characters to separate fields with (default is \t)
     20     -s	sequential mode: turn each input file into one line of output
     21 */
     22 
     23 #define FOR_paste
     24 #include "toys.h"
     25 
     26 GLOBALS(
     27   char *d;
     28 
     29   int files;
     30 )
     31 
     32 // \0 is weird, and -d "" is also weird.
     33 
     34 static void paste_files(void)
     35 {
     36   FILE **fps = (void *)toybuf;
     37   char *dpos, *dstr, *buf, c;
     38   int i, any, dcount, dlen, len, seq = toys.optflags&FLAG_s;
     39 
     40   // Loop through lines until no input left
     41   for (;;) {
     42 
     43     // Start of each line/file resets delimiter cycle
     44     dpos = TT.d;
     45 
     46     for (i = any = dcount = dlen = 0; seq || i<TT.files; i++) {
     47       size_t blen;
     48       wchar_t wc;
     49       FILE *ff = seq ? *fps : fps[i];
     50 
     51       // Read and output line, preserving embedded NUL bytes.
     52 
     53       buf = 0;
     54       len = 0;
     55       if (!ff || 0>=(len = getline(&buf, &blen, ff))) {
     56         if (ff && ff!=stdin) fclose(ff);
     57         if (seq) return;
     58         fps[i] = 0;
     59         if (!any) continue;
     60       }
     61       dcount = any ? 1 : i;
     62       any = 1;
     63 
     64       // Output delimiters as necessary: not at beginning/end of line,
     65       // catch up if first few files had no input but a later one did.
     66       // Entire line with no input means no output.
     67 
     68       while (dcount) {
     69 
     70         // Find next delimiter, which can be "", \n, or UTF8 w/combining chars
     71         dstr = dpos;
     72         dlen = 0;
     73         dcount--;
     74 
     75         if (!*TT.d) {;}
     76         else if (*dpos == '\\') {
     77           if (*++dpos=='0') dpos++;
     78           else {
     79             dlen = 1;
     80             if ((c = unescape(*dpos))) {
     81               dstr = &c;
     82               dpos++;
     83             }
     84           }
     85         } else {
     86           while (0<(dlen = utf8towc(&wc, dpos, 99))) {
     87             dpos += dlen;
     88             if (!(dlen = wcwidth(wc))) continue;
     89             if (dlen<0) dpos = dstr+1;
     90             break;
     91           }
     92           dlen = dpos-dstr;
     93         }
     94         if (!*dpos) dpos = TT.d;
     95 
     96         if (dlen) fwrite(dstr, dlen, 1, stdout);
     97       }
     98 
     99       if (0<len) {
    100         fwrite(buf, len-(buf[len-1]=='\n'), 1, stdout);
    101         free(buf);
    102       }
    103     }
    104 
    105     // Only need a newline if we output something
    106     if (any) xputc('\n');
    107     else break;
    108   }
    109 }
    110 
    111 static void do_paste(int fd, char *name)
    112 {
    113   FILE **fps = (void *)toybuf;
    114 
    115   if (!(fps[TT.files++] = (fd ? fdopen(fd, "r") : stdin))) perror_exit(0);
    116   if (TT.files >= sizeof(toybuf)/sizeof(FILE *)) perror_exit("tilt");
    117   if (toys.optflags&FLAG_s) {
    118     paste_files();
    119     xputc('\n');
    120     TT.files = 0;
    121   }
    122 }
    123 
    124 void paste_main(void)
    125 {
    126   if (!(toys.optflags&FLAG_d)) TT.d = "\t";
    127 
    128   loopfiles_rw(toys.optargs, O_RDONLY, 0, do_paste);
    129   if (!(toys.optflags&FLAG_s)) paste_files();
    130 }
    131