Move 'builtin-*' into a 'builtin/' subdirectory

[git.git] / builtin / stripspace.c

diff --git a/builtin/stripspace.c b/builtin/stripspace.c
new file mode 100644 (file)
index 0000000..4d3b93f
--- /dev/null
+++ b/builtin/stripspace.c
@@ -0,0 +1,90 @@
+#include "builtin.h"
+#include "cache.h"
+
+/*
+ * Returns the length of a line, without trailing spaces.
+ *
+ * If the line ends with newline, it will be removed too.
+ */
+static size_t cleanup(char *line, size_t len)
+{
+       while (len) {
+               unsigned char c = line[len - 1];
+               if (!isspace(c))
+                       break;
+               len--;
+       }
+
+       return len;
+}
+
+/*
+ * Remove empty lines from the beginning and end
+ * and also trailing spaces from every line.
+ *
+ * Note that the buffer will not be NUL-terminated.
+ *
+ * Turn multiple consecutive empty lines between paragraphs
+ * into just one empty line.
+ *
+ * If the input has only empty lines and spaces,
+ * no output will be produced.
+ *
+ * If last line does not have a newline at the end, one is added.
+ *
+ * Enable skip_comments to skip every line starting with "#".
+ */
+void stripspace(struct strbuf *sb, int skip_comments)
+{
+       int empties = 0;
+       size_t i, j, len, newlen;
+       char *eol;
+
+       /* We may have to add a newline. */
+       strbuf_grow(sb, 1);
+
+       for (i = j = 0; i < sb->len; i += len, j += newlen) {
+               eol = memchr(sb->buf + i, '\n', sb->len - i);
+               len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
+
+               if (skip_comments && len && sb->buf[i] == '#') {
+                       newlen = 0;
+                       continue;
+               }
+               newlen = cleanup(sb->buf + i, len);
+
+               /* Not just an empty line? */
+               if (newlen) {
+                       if (empties > 0 && j > 0)
+                               sb->buf[j++] = '\n';
+                       empties = 0;
+                       memmove(sb->buf + j, sb->buf + i, newlen);
+                       sb->buf[newlen + j++] = '\n';
+               } else {
+                       empties++;
+               }
+       }
+
+       strbuf_setlen(sb, j);
+}
+
+int cmd_stripspace(int argc, const char **argv, const char *prefix)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int strip_comments = 0;
+
+       if (argc == 2 && (!strcmp(argv[1], "-s") ||
+                               !strcmp(argv[1], "--strip-comments")))
+               strip_comments = 1;
+       else if (argc > 1)
+               usage("git stripspace [-s | --strip-comments] < <stream>");
+
+       if (strbuf_read(&buf, 0, 1024) < 0)
+               die_errno("could not read the input");
+
+       stripspace(&buf, strip_comments);
+
+       write_or_die(1, buf.buf, buf.len);
+       strbuf_release(&buf);
+       return 0;
+}