coreutils/paste.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * paste.c - implementation of the posix paste command
   4  *
   5  * Written by Maxime Coste <mawww@kakoune.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9 //config:config PASTE
  10 //config:       bool "paste (5.1 kb)"
  11 //config:       default y
  12 //config:       help
  13 //config:       paste is used to paste lines of different files together
  14 //config:       and write the result to stdout
  15
  16 //applet:IF_PASTE(APPLET_NOEXEC(paste, paste, BB_DIR_USR_BIN, BB_SUID_DROP, paste))
  17
  18 //kbuild:lib-$(CONFIG_PASTE) += paste.o
  19
  20 //usage:#define paste_trivial_usage
  21 //usage:       "[-d LIST] [-s] [FILE]..."
  22 //usage:#define paste_full_usage "\n\n"
  23 //usage:       "Paste lines from each input file, separated with tab\n"
  24 //usage:     "\n        -d LIST Use delimiters from LIST, not tab"
  25 //usage:     "\n        -s      Serial: one file at a time"
  26 //usage:
  27 //usage:#define paste_example_usage
  28 //usage:       "# write out directory in four columns\n"
  29 //usage:       "$ ls | paste - - - -\n"
  30 //usage:       "# combine pairs of lines from a file into single lines\n"
  31 //usage:       "$ paste -s -d '\\t\\n' file\n"
  32
  33 #include "libbb.h"
  34
  35 static void paste_files(FILE** files, int file_cnt, char* delims, int del_cnt)
  36 {
  37         char *line;
  38         char delim;
  39         int active_files = file_cnt;
  40         int i;
  41
  42         while (active_files > 0) {
  43                 int del_idx = 0;
  44
  45                 for (i = 0; i < file_cnt; ++i) {
  46                         if (files[i] == NULL)
  47                                 continue;
  48
  49                         line = xmalloc_fgetline(files[i]);
  50                         if (!line) {
  51                                 fclose_if_not_stdin(files[i]);
  52                                 files[i] = NULL;
  53                                 --active_files;
  54                                 continue;
  55                         }
  56                         fputs_stdout(line);
  57                         free(line);
  58                         delim = '\n';
  59                         if (i != file_cnt - 1) {
  60                                 delim = delims[del_idx++];
  61                                 if (del_idx == del_cnt)
  62                                         del_idx = 0;
  63                         }
  64                         if (delim != '\0')
  65                                 fputc(delim, stdout);
  66                 }
  67         }
  68 }
  69
  70 static void paste_files_separate(FILE** files, char* delims, int del_cnt)
  71 {
  72         char *line, *next_line;
  73         char delim;
  74         int i;
  75
  76         for (i = 0; files[i]; ++i) {
  77                 int del_idx = 0;
  78
  79                 line = NULL;
  80                 while ((next_line = xmalloc_fgetline(files[i])) != NULL) {
  81                         if (line) {
  82                                 fputs_stdout(line);
  83                                 free(line);
  84                                 delim = delims[del_idx++];
  85                                 if (del_idx == del_cnt)
  86                                         del_idx = 0;
  87                                 if (delim != '\0')
  88                                         fputc(delim, stdout);
  89                         }
  90                         line = next_line;
  91                 }
  92                 if (line) {
  93                         /* coreutils adds \n even if this is a final line
  94                          * of the last file and it was not \n-terminated.
  95                          */
  96                         printf("%s\n", line);
  97                         free(line);
  98                 }
  99                 fclose_if_not_stdin(files[i]);
 100         }
 101 }
 102
 103 #define PASTE_OPT_DELIMITERS (1 << 0)
 104 #define PASTE_OPT_SEPARATE   (1 << 1)
 105
 106 int paste_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 107 int paste_main(int argc UNUSED_PARAM, char **argv)
 108 {
 109         char *delims = (char*)"\t";
 110         int del_cnt = 1;
 111         unsigned opt;
 112         int i;
 113
 114         opt = getopt32(argv, "d:s", &delims);
 115         argv += optind;
 116
 117         if (opt & PASTE_OPT_DELIMITERS) {
 118                 if (!delims[0])
 119                         bb_simple_error_msg_and_die("-d '' is not supported");
 120                 /* unknown mappings are not changed: "\z" -> '\\' 'z' */
 121                 /* trailing backslash, if any, is preserved */
 122                 del_cnt = strcpy_and_process_escape_sequences(delims, delims) - delims;
 123                 /* note: handle NUL properly (do not stop at it!): try -d'\t\0\t' */
 124         }
 125
 126         if (!argv[0])
 127                 (--argv)[0] = (char*) "-";
 128         for (i = 0; argv[i]; ++i) {
 129                 argv[i] = (void*) fopen_or_warn_stdin(argv[i]);
 130                 if (!argv[i])
 131                         xfunc_die();
 132         }
 133
 134         if (opt & PASTE_OPT_SEPARATE)
 135                 paste_files_separate((FILE**)argv, delims, del_cnt);
 136         else
 137                 paste_files((FILE**)argv, i, delims, del_cnt);
 138
 139         fflush_stdout_and_exit(0);
 140 }