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"
  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-$(CONFIG_PASTE) += paste.o
  19
  20 //usage:#define paste_trivial_usage
  21 //usage:       "[OPTIONS] [FILE]..."
  22 //usage:#define paste_full_usage "\n\n"
  23 //usage:       "Paste lines from each input file, seperated with tab\n"
  24 //usage:     "\n        -d LIST Use delimiters from LIST, not tab"
  25 //usage:     "\n        -s      Serial: one file at a time"
  26 //usage:
  27 //usage:#define paste_example_usage
  28 //usage:       "# write out directory in four columns\n"
  29 //usage:       "$ 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 del_idx = 0;
  40         int active_files = file_cnt;
  41         int i;
  42
  43         while (active_files > 0) {
  44                 for (i = 0; i < file_cnt; ++i) {
  45                         if (files[i] == NULL)
  46                                 continue;
  47
  48                         line = xmalloc_fgetline(files[i]);
  49                         if (!line) {
  50                                 fclose_if_not_stdin(files[i]);
  51                                 files[i] = NULL;
  52                                 --active_files;
  53                                 continue;
  54                         }
  55                         fputs(line, stdout);
  56                         free(line);
  57                         delim = '\n';
  58                         if (i != file_cnt - 1) {
  59                                 delim = delims[del_idx++];
  60                                 if (del_idx == del_cnt)
  61                                         del_idx = 0;
  62                         }
  63                         if (delim != '\0')
  64                                 fputc(delim, stdout);
  65                 }
  66         }
  67 }
  68
  69 static void paste_files_separate(FILE** files, char* delims, int del_cnt)
  70 {
  71         char *line, *next_line;
  72         char delim;
  73         int del_idx = 0;
  74         int i;
  75
  76         for (i = 0; files[i]; ++i) {
  77                 line = NULL;
  78                 while ((next_line = xmalloc_fgetline(files[i])) != NULL) {
  79                         if (line) {
  80                                 fputs(line, stdout);
  81                                 free(line);
  82                                 delim = delims[del_idx++];
  83                                 if (del_idx == del_cnt)
  84                                         del_idx = 0;
  85                                 if (delim != '\0')
  86                                         fputc(delim, stdout);
  87                         }
  88                         line = next_line;
  89                 }
  90                 if (line) {
  91                         /* coreutils adds \n even if this is a final line
  92                          * of the last file and it was not \n-terminated.
  93                          */
  94                         printf("%s\n", line);
  95                         free(line);
  96                 }
  97                 fclose_if_not_stdin(files[i]);
  98         }
  99 }
 100
 101 #define PASTE_OPT_DELIMITERS (1 << 0)
 102 #define PASTE_OPT_SEPARATE   (1 << 1)
 103
 104 int paste_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 105 int paste_main(int argc UNUSED_PARAM, char **argv)
 106 {
 107         char *delims = (char*)"\t";
 108         int del_cnt = 1;
 109         unsigned opt;
 110         int i;
 111
 112         opt = getopt32(argv, "d:s", &delims);
 113         argv += optind;
 114
 115         if (opt & PASTE_OPT_DELIMITERS) {
 116                 if (!delims[0])
 117                         bb_error_msg_and_die("-d '' is not supported");
 118                 /* unknown mappings are not changed: "\z" -> '\\' 'z' */
 119                 /* trailing backslash, if any, is preserved */
 120                 del_cnt = strcpy_and_process_escape_sequences(delims, delims) - delims;
 121                 /* note: handle NUL properly (do not stop at it!): try -d'\t\0\t' */
 122         }
 123
 124         if (!argv[0])
 125                 (--argv)[0] = (char*) "-";
 126         for (i = 0; argv[i]; ++i) {
 127                 argv[i] = (void*) fopen_or_warn_stdin(argv[i]);
 128                 if (!argv[i])
 129                         xfunc_die();
 130         }
 131
 132         if (opt & PASTE_OPT_SEPARATE)
 133                 paste_files_separate((FILE**)argv, delims, del_cnt);
 134         else
 135                 paste_files((FILE**)argv, i, delims, del_cnt);
 136
 137         fflush_stdout_and_exit(0);
 138 }