Merge branch 'jc/usage-stdin' into maint

The synopsis text and the usage string of subcommands that read
list of things from the standard input are often shown as if they
only take input from a file on a filesystem, which was misleading.

* jc/usage-stdin:
usage: do not insist that standard input must come from a file

diff --combined builtin/stripspace.c
index a8b7a93b43e414b51c76a4853ff3b49394ab1d77,958567a0cd0f3b676f2a46a699b34a67d14f129a..7ff8434f7c3cf71dbd77cbf868d5dc56dd943fdb
--- 1/builtin/stripspace.c
--- 2/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@@ -1,7 -1,71 +1,7 @@@
  #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.
 - *
 - * 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 comment
 - * character.
 - */
 -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] == comment_line_char) {
 -                      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);
 -}
 +#include "parse-options.h"
 +#include "strbuf.h"
  
  static void comment_lines(struct strbuf *buf)
  {
@@@ -13,45 -77,41 +13,45 @@@
        free(msg);
  }
  
 -static const char *usage_msg = "\n"
 -"  git stripspace [-s | --strip-comments]\n"
 -"  git stripspace [-c | --comment-lines]";
 +static const char * const stripspace_usage[] = {
-       N_("git stripspace [-s | --strip-comments] < input"),
-       N_("git stripspace [-c | --comment-lines] < input"),
++      N_("git stripspace [-s | --strip-comments]"),
++      N_("git stripspace [-c | --comment-lines]"),
 +      NULL
 +};
 +
 +enum stripspace_mode {
 +      STRIP_DEFAULT = 0,
 +      STRIP_COMMENTS,
 +      COMMENT_LINES
 +};
  
  int cmd_stripspace(int argc, const char **argv, const char *prefix)
  {
        struct strbuf buf = STRBUF_INIT;
 -      int strip_comments = 0;
 -      enum { INVAL = 0, STRIP_SPACE = 1, COMMENT_LINES = 2 } mode = STRIP_SPACE;
 -
 -      if (argc == 2) {
 -              if (!strcmp(argv[1], "-s") ||
 -                  !strcmp(argv[1], "--strip-comments")) {
 -                      strip_comments = 1;
 -              } else if (!strcmp(argv[1], "-c") ||
 -                         !strcmp(argv[1], "--comment-lines")) {
 -                      mode = COMMENT_LINES;
 -              } else {
 -                      mode = INVAL;
 -              }
 -      } else if (argc > 1) {
 -              mode = INVAL;
 -      }
 -
 -      if (mode == INVAL)
 -              usage(usage_msg);
 -
 -      if (strip_comments || mode == COMMENT_LINES)
 +      enum stripspace_mode mode = STRIP_DEFAULT;
 +
 +      const struct option options[] = {
 +              OPT_CMDMODE('s', "strip-comments", &mode,
 +                          N_("skip and remove all lines starting with comment character"),
 +                          STRIP_COMMENTS),
 +              OPT_CMDMODE('c', "comment-lines", &mode,
 +                          N_("prepend comment character and blank to each line"),
 +                          COMMENT_LINES),
 +              OPT_END()
 +      };
 +
 +      argc = parse_options(argc, argv, prefix, options, stripspace_usage, 0);
 +      if (argc)
 +              usage_with_options(stripspace_usage, options);
 +
 +      if (mode == STRIP_COMMENTS || mode == COMMENT_LINES)
                git_config(git_default_config, NULL);
  
        if (strbuf_read(&buf, 0, 1024) < 0)
                die_errno("could not read the input");
  
 -      if (mode == STRIP_SPACE)
 -              stripspace(&buf, strip_comments);
 +      if (mode == STRIP_DEFAULT || mode == STRIP_COMMENTS)
 +              strbuf_stripspace(&buf, mode == STRIP_COMMENTS);
        else
                comment_lines(&buf);