git-filter-branch: document --original option

[git.git] / builtin-stripspace.c

diff --git a/builtin-stripspace.c b/builtin-stripspace.c
index f0d4d9e2d10446a229094c991363f5a17ce4c666..916355ca5d04ec571d4100c98b969b693c830a18 100644 (file)
--- a/builtin-stripspace.c
+++ b/builtin-stripspace.c
@@ -1,58 +1,99 @@
 #include "builtin.h"
+#include "cache.h"
 
 /*
- * Remove empty lines from the beginning and end.
+ * Returns the length of a line, without trailing spaces.
  *
- * Turn multiple consecutive empty lines into just one
- * empty line.  Return true if it is an incomplete line.
+ * If the line ends with newline, it will be removed too.
  */
-static int cleanup(char *line)
+static size_t cleanup(char *line, size_t len)
 {
-       int len = strlen(line);
+       if (len) {
+               if (line[len - 1] == '\n')
+                       len--;
 
-       if (len && line[len-1] == '\n') {
-               if (len == 1)
-                       return 0;
-               do {
-                       unsigned char c = line[len-2];
+               while (len) {
+                       unsigned char c = line[len - 1];
                        if (!isspace(c))
                                break;
-                       line[len-2] = '\n';
                        len--;
-                       line[len] = 0;
-               } while (len > 1);
-               return 0;
+               }
        }
-       return 1;
+       return len;
 }
 
-void stripspace(FILE *in, FILE *out)
+/*
+ * 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 has a newline at the end, it will be removed.
+ *
+ * Enable skip_comments to skip every line starting with "#".
+ */
+size_t stripspace(char *buffer, size_t length, int skip_comments)
 {
        int empties = -1;
-       int incomplete = 0;
-       char line[1024];
+       size_t i, j, len, newlen;
+       char *eol;
 
-       while (fgets(line, sizeof(line), in)) {
-               incomplete = cleanup(line);
+       for (i = j = 0; i < length; i += len, j += newlen) {
+               eol = memchr(buffer + i, '\n', length - i);
+               len = eol ? eol - (buffer + i) + 1 : length - i;
+
+               if (skip_comments && len && buffer[i] == '#') {
+                       newlen = 0;
+                       continue;
+               }
+               newlen = cleanup(buffer + i, len);
 
                /* Not just an empty line? */
-               if (line[0] != '\n') {
+               if (newlen) {
+                       if (empties != -1)
+                               buffer[j++] = '\n';
                        if (empties > 0)
-                               fputc('\n', out);
+                               buffer[j++] = '\n';
                        empties = 0;
-                       fputs(line, out);
+                       memmove(buffer + j, buffer + i, newlen);
                        continue;
                }
                if (empties < 0)
                        continue;
                empties++;
        }
-       if (incomplete)
-               fputc('\n', out);
+
+       return j;
 }
 
 int cmd_stripspace(int argc, const char **argv, const char *prefix)
 {
-       stripspace(stdin, stdout);
+       char *buffer;
+       unsigned long size;
+       int strip_comments = 0;
+
+       if (argc > 1 && (!strcmp(argv[1], "-s") ||
+                               !strcmp(argv[1], "--strip-comments")))
+               strip_comments = 1;
+
+       size = 1024;
+       buffer = xmalloc(size);
+       if (read_fd(0, &buffer, &size)) {
+               free(buffer);
+               die("could not read the input");
+       }
+
+       size = stripspace(buffer, size, strip_comments);
+       write_or_die(1, buffer, size);
+       if (size)
+               putc('\n', stdout);
+
+       free(buffer);
        return 0;
 }