config.c: Expand $HOME and tilde character in core.excludesfile

c* str_replace(): New function. Generic replace command.
* str_replace_home(): New funtion. Substitute $HOME and tilde(~) in string.
* git_default_config(): Pass core.excludesfile to str_replace_home().

---

From ac6941f5055b2acdded59627d228bbf03ba0d9fc

 config.c |   44 +++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 43 insertions(+), 1 deletions(-)

index 526a3f4..7c91689 100644
@@ -309,6 +309,46 @@ int git_config_bool(const char *name, const char *value)
 	return git_config_int(name, value) != 0;
 }
 
+char *str_replace(const char *str, const char *find, const char *replace)
+{
+        int maxlen   = strlen(str) + strlen(replace) + 1;
+        char *start  = strstr(str, find);
+        char *ptr    = (char *)malloc(maxlen);
+        int len      = strlen(find);
+        int llen, rlen;         /* left, right portion length */
+
+        if (start == (char *)NULL) {
+                strcpy( ptr, str);
+        }
+        else{
+                rlen = strlen(start) - strlen(find);
+                llen = strlen(str) - strlen(start);
+                strncpy( ptr, str, llen);
+                strcat( ptr, replace);
+                strncat( ptr, start + len, rlen); /* Does not add  '\0' */
+                strcat( ptr, "");   /* Terminate with null string */
+        }
+
+        return ptr;
+}
+
+char *str_replace_home(const char *str)
+{
+        char *ret  = xstrdup(str);
+        char *home = getenv("HOME");
+
+        if (home != (char *)NULL ) {
+                if (strstr(str, "~") != NULL) {
+                        ret = str_replace(str, "~", home);
+                }
+                else if (strstr(str, "$HOME") != NULL) {
+                        ret = str_replace(str, "$HOME", home);
+                }
+        }
+
+        return ret;
+}
+
 int git_default_config(const char *var, const char *value)
 {
 	/* This needs a better name */

@@ -447,7 +487,9 @@ int git_default_config(const char *var, const char *value)
 		if (!value)
 			die("core.excludesfile without value");
 		excludes_file = xstrdup(value);
-		return 0;
+                /* expand $HOME and tilde(~) */
+                excludes_file = str_replace_home(excludes_file);
+                return 0;
 	}
 
 	if (!strcmp(var, "core.whitespace")) {

1.5.4-rc3.GIT

This would mangle a name with a tilde in it, e.g. "file.c~", etc.

This would affect similarly named vars, e.g. $HOMER, etc.

Calling strcat() requires a null-terminated string. Instead, assign a '\0' char at the right position.

..wayne..

Hi,

I don't like it. Not only do you fail to provide an example where this could be useful, you also introduce a memory leak for every excludes setting.

Besides, there is a more fundamental reason to reject this patch: it sets a path for an excludes file for everybody, but to a file which usually does not exist.

So either the user creates that file, in which case you can expect her to adjust ~/.gitconfig, too, or it is not created, in which case the setting in /etc/gitconfig is useless.

There is also a third option: there is a file created for every user from /etc/skel, but then there can also be a ~/.gitconfig.

Ciao,
Dscho

First, git project does NOT use GNU ChangeLog convention for it's commit messages. We rather use descriptive commit messages.

Second, I'm not sure about str_replace... how it fits with strbufs? AFAIK we try to use strbufs whenever possible and feasible, to avoid errors in git.

Third, I agree that it is a good idea, but I'd rather have *full* solution, i.e. for git to expand $HOME (or better yet any environmental variable) and '~' everywhere, not only for core.excludesfile, but also for --git-dir and GIT_DIR, for core.worktree and --work-tree and GIT_WORK_TREE, and for all other config variables and enviroment variables.

What does it mean? A bit cryptic, don't you think?

Comments on code below. One thing: we use tabs for indent, not spaces. You use spaces in your code, while context uses tabs.

Style: no space after opening parenthesis: "strcpy(ptr, str)".
Performance: I think it would be better to use stpcpy, although I'm not quite sure if here too.

Jakub Narebski
Poland
ShadeHawk on #git

Not that what Jari wrote had much resemblance to GNU ChangeLog format...

-Miles

Opposition, n. In politics the party that prevents the Goverment from running
amok by hamstringing it.

What, like http://www.gnu.org/prep/standards/html_node/Style-of-Change-Logs.html#Style-of-Change-Logs
? It looked like GNU style to me.

Dave.

No, all the details are wrong. Just about the only thing in common with ChangeLog format is that he used asterisks as bullets, and a colon to indicate the descriptive text -- but that's simply what people tend to do when making an itemized list in ascii...

-Miles

Do not taunt Happy Fun Ball.