[PATCH v3] pretty.c: add %x00 format specifier.

[PATCH v3] pretty.c: add %x00 format specifier.

[Govind Salinas]

This adds a %x00 format which parses the 00 as hex encoding for a byte and
prints the resulting byte.  This can be used to add null bytes or other bytes
that can make machine parsing easier.  It is also necessary to use fwrite to
print out the data since printf will terminate if you feed it a null.

Junio supplied the hex decoding.

Signed-off-by: Govind Salinas <blix@sophiasuchtig.com>
---
 Documentation/pretty-formats.txt |    1 +
 log-tree.c                       |    6 ++++--
 pretty.c                         |   11 +++++++++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 0193c3c..e8bea3e 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -123,3 +123,4 @@ The placeholders are:
 - '%Creset': reset color
 - '%m': left, right or boundary mark
 - '%n': newline
+- '%x00': print a byte from a hex code
diff --git a/log-tree.c b/log-tree.c
index 608f697..3bb6e49 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -308,8 +308,10 @@ void show_log(struct rev_info *opt, const char *sep)
 	if (opt->show_log_size)
 		printf("log size %i\n", (int)msgbuf.len);

-	if (msgbuf.len)
-		printf("%s%s%s", msgbuf.buf, extra, sep);
+	if (msgbuf.len) {
+		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
+		printf("%s%s", extra, sep);
+	}
 	strbuf_release(&msgbuf);
 }

diff --git a/pretty.c b/pretty.c
index 703f521..cb4944c 100644
--- a/pretty.c
+++ b/pretty.c
@@ -457,6 +457,7 @@ static size_t format_commit_item(struct strbuf
*sb, const char *placeholder,
 	const struct commit *commit = c->commit;
 	const char *msg = commit->buffer;
 	struct commit_list *p;
+	int h1, h2;

 	/* these are independent of the commit */
 	switch (placeholder[0]) {
@@ -478,6 +479,16 @@ static size_t format_commit_item(struct strbuf
*sb, const char *placeholder,
 	case 'n':		/* newline */
 		strbuf_addch(sb, '\n');
 		return 1;
+	case 'x':
+		/* %x00 == NUL, %x0a == LF, etc. */
+		if (0 <= (h1 = hexval_table[0xff & placeholder[1]]) &&
+		    h1 <= 16 &&
+		    0 <= (h2 = hexval_table[0xff & placeholder[2]]) &&
+		    h2 <= 16) {
+			strbuf_addch(sb, (h1<<4)|h2);
+			return 3;
+		} else
+			return 0;
 	}

 	/* these depend on the commit */
-- 
1.5.4.4.552.g7113.dirty

Re: [PATCH v3] pretty.c: add %x00 format specifier.

[Johannes Schindelin]

Hi,

On Fri, 21 Mar 2008, Govind Salinas wrote:

> This adds a %x00 format which parses the 00 as hex encoding for a byte 
> and prints the resulting byte.  This can be used to add null bytes or 
> other bytes that can make machine parsing easier.  It is also necessary 
> to use fwrite to print out the data since printf will terminate if you 
> feed it a null.
> 
> Junio supplied the hex decoding.

This is all nice and well, but if I understood you correctly, your 
original aim was to have a pretty-formatted list of the revisions, but 
NUL-delimited for easy parsing.

Which you can do with "git log --pretty=format:%s -z" right now.

Ciao,
Dscho

Re: [PATCH v3] pretty.c: add %x00 format specifier.

[Govind Salinas]

On Fri, Mar 21, 2008 at 10:47 AM, Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
>
>  On Fri, 21 Mar 2008, Govind Salinas wrote:
>
>  > This adds a %x00 format which parses the 00 as hex encoding for a byte
>  > and prints the resulting byte.  This can be used to add null bytes or
>  > other bytes that can make machine parsing easier.  It is also necessary
>  > to use fwrite to print out the data since printf will terminate if you
>  > feed it a null.
>  >
>  > Junio supplied the hex decoding.
>
>  This is all nice and well, but if I understood you correctly, your
>  original aim was to have a pretty-formatted list of the revisions, but
>  NUL-delimited for easy parsing.
>
>  Which you can do with "git log --pretty=format:%s -z" right now.
>
>  Ciao,
>  Dscho
>
>

Unfortunately that almost work for me.  I am in the following situation
If I stick to just using the --pretty=format options then I would be fine
but I am also adding --stat and -p to git-log, so now I have 3 multiline
hunks of data and I need to tell where each one ends deterministically.
I *could* just look for "---" and "diff  --git" at every line but I would prefer
to use a delimiter.

Alternatively, if -z would add a null before the diffstat was printed, that
would probably work for me as well.  Even so, using the same delimiter
is nicer than parsing part with newlines and part with nulls, which I would
have to do if I just used -z.  Think
"%H%x00%ae%x00%an%x00%s%x00%b%x00 -z -p --stat". there
everything splits nicely with nulls.  The alternative (with -z adding a null
before the diffstat is "%H%n%ae%n%an%n%s%n%b -z -p --stat" which
would work, but I would have to parse the last 3 fields differently.

Perhaps there is a better way to get all this information.  But I do want
all the information to come from the same call.

Thanks,
Govind.

Re: [PATCH v3] pretty.c: add %x00 format specifier.

[Govind Salinas]

On Fri, Mar 21, 2008 at 12:45 PM, Govind Salinas
<govind@sophiasuchtig.com> wrote:
>
> On Fri, Mar 21, 2008 at 10:47 AM, Johannes Schindelin
>  <Johannes.Schindelin@gmx.de> wrote:
>  > Hi,
>  >
>  >
>  >  On Fri, 21 Mar 2008, Govind Salinas wrote:
>  >
>  >  > This adds a %x00 format which parses the 00 as hex encoding for a byte
>  >  > and prints the resulting byte.  This can be used to add null bytes or
>  >  > other bytes that can make machine parsing easier.  It is also necessary
>  >  > to use fwrite to print out the data since printf will terminate if you
>  >  > feed it a null.
>  >  >
>  >  > Junio supplied the hex decoding.
>  >
>  >  This is all nice and well, but if I understood you correctly, your
>  >  original aim was to have a pretty-formatted list of the revisions, but
>  >  NUL-delimited for easy parsing.
>  >
>  >  Which you can do with "git log --pretty=format:%s -z" right now.
>  >
>  >  Ciao,
>  >  Dscho
>  >
>  >
>
>  Unfortunately that almost work for me.  I am in the following situation
>  If I stick to just using the --pretty=format options then I would be fine
>  but I am also adding --stat and -p to git-log, so now I have 3 multiline
>  hunks of data and I need to tell where each one ends deterministically.
>  I *could* just look for "---" and "diff  --git" at every line but I would prefer
>  to use a delimiter.
>
>  Alternatively, if -z would add a null before the diffstat was printed, that
>  would probably work for me as well.  Even so, using the same delimiter
>  is nicer than parsing part with newlines and part with nulls, which I would
>  have to do if I just used -z.  Think
>  "%H%x00%ae%x00%an%x00%s%x00%b%x00 -z -p --stat". there
>  everything splits nicely with nulls.  The alternative (with -z adding a null
>  before the diffstat is "%H%n%ae%n%an%n%s%n%b -z -p --stat" which
>  would work, but I would have to parse the last 3 fields differently.
>
>  Perhaps there is a better way to get all this information.  But I do want
>  all the information to come from the same call.
>
>  Thanks,
>  Govind.
>

Ok, how about this instead?  Perhaps it is more palatable.

diff --git a/log-tree.c b/log-tree.c
index 608f697..5f55683 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -338,7 +338,7 @@ int log_tree_diff_flush(struct rev_info *opt)
                        int pch = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_PATCH;
                        if ((pch & opt->diffopt.output_format) == pch)
                                printf("---");
-                       putchar('\n');
+                       putchar(opt->diffopt.line_termination);
                }
        }
        diff_flush(&opt->diffopt);