builtin/stripspace.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3
   4 /*
   5  * Returns the length of a line, without trailing spaces.
   6  *
   7  * If the line ends with newline, it will be removed too.
   8  */
   9 static size_t cleanup(char *line, size_t len)
  10 {
  11         while (len) {
  12                 unsigned char c = line[len - 1];
  13                 if (!isspace(c))
  14                         break;
  15                 len--;
  16         }
  17
  18         return len;
  19 }
  20
  21 /*
  22  * Remove empty lines from the beginning and end
  23  * and also trailing spaces from every line.
  24  *
  25  * Turn multiple consecutive empty lines between paragraphs
  26  * into just one empty line.
  27  *
  28  * If the input has only empty lines and spaces,
  29  * no output will be produced.
  30  *
  31  * If last line does not have a newline at the end, one is added.
  32  *
  33  * Enable skip_comments to skip every line starting with comment
  34  * character.
  35  */
  36 void stripspace(struct strbuf *sb, int skip_comments)
  37 {
  38         int empties = 0;
  39         size_t i, j, len, newlen;
  40         char *eol;
  41
  42         /* We may have to add a newline. */
  43         strbuf_grow(sb, 1);
  44
  45         for (i = j = 0; i < sb->len; i += len, j += newlen) {
  46                 eol = memchr(sb->buf + i, '\n', sb->len - i);
  47                 len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
  48
  49                 if (skip_comments && len && sb->buf[i] == comment_line_char) {
  50                         newlen = 0;
  51                         continue;
  52                 }
  53                 newlen = cleanup(sb->buf + i, len);
  54
  55                 /* Not just an empty line? */
  56                 if (newlen) {
  57                         if (empties > 0 && j > 0)
  58                                 sb->buf[j++] = '\n';
  59                         empties = 0;
  60                         memmove(sb->buf + j, sb->buf + i, newlen);
  61                         sb->buf[newlen + j++] = '\n';
  62                 } else {
  63                         empties++;
  64                 }
  65         }
  66
  67         strbuf_setlen(sb, j);
  68 }
  69
  70 static void comment_lines(struct strbuf *buf)
  71 {
  72         char *msg;
  73         size_t len;
  74
  75         msg = strbuf_detach(buf, &len);
  76         strbuf_add_commented_lines(buf, msg, len);
  77         free(msg);
  78 }
  79
  80 static const char *usage_msg = "\n"
  81 "  git stripspace [-s | --strip-comments] < input\n"
  82 "  git stripspace [-c | --comment-lines] < input";
  83
  84 int cmd_stripspace(int argc, const char **argv, const char *prefix)
  85 {
  86         struct strbuf buf = STRBUF_INIT;
  87         int strip_comments = 0;
  88         enum { INVAL = 0, STRIP_SPACE = 1, COMMENT_LINES = 2 } mode = STRIP_SPACE;
  89
  90         if (argc == 2) {
  91                 if (!strcmp(argv[1], "-s") ||
  92                     !strcmp(argv[1], "--strip-comments")) {
  93                         strip_comments = 1;
  94                 } else if (!strcmp(argv[1], "-c") ||
  95                            !strcmp(argv[1], "--comment-lines")) {
  96                         mode = COMMENT_LINES;
  97                 } else {
  98                         mode = INVAL;
  99                 }
 100         } else if (argc > 1) {
 101                 mode = INVAL;
 102         }
 103
 104         if (mode == INVAL)
 105                 usage(usage_msg);
 106
 107         if (strip_comments || mode == COMMENT_LINES)
 108                 git_config(git_default_config, NULL);
 109
 110         if (strbuf_read(&buf, 0, 1024) < 0)
 111                 die_errno("could not read the input");
 112
 113         if (mode == STRIP_SPACE)
 114                 stripspace(&buf, strip_comments);
 115         else
 116                 comment_lines(&buf);
 117
 118         write_or_die(1, buf.buf, buf.len);
 119         strbuf_release(&buf);
 120         return 0;
 121 }