Allow custom "comment char"
[git/git.git] / 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 }