[pacman-dev] [PATCH] Allow -Qo to perform a functional 'which'

[Allan McRae]

When pacman queries the ownership of an object that is not a path,
it will check in the users PATH for a match. Implements FS#8798.

Original-patch-by: Shankar <jatheendra at gmail.com>
Signed-off-by: Allan McRae <allan at archlinux.org>
---

This should address all comments I had when this was submitted a
few months back.

 src/pacman/query.c |   57 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/src/pacman/query.c b/src/pacman/query.c
index 6b6a25d..038072f 100644
--- a/src/pacman/query.c
+++ b/src/pacman/query.c
@@ -56,10 +56,44 @@ static char *resolve_path(const char* file)
 	return(str);
 }
 
+/* check if filename exists in PATH */
+static int search_path(char *filename, size_t size, struct stat * bufptr)
+{
+	char *envpath, *envpathsplit, *path, fullname[PATH_MAX+1];
+	int len;
+
+	if ((envpath = getenv("PATH")) == NULL) {
+		return(-1);
+	}
+	if ((envpath = envpathsplit = strdup(envpath)) == NULL) {
+		return(-1);
+	}
+
+	while ((path = strsep(&envpathsplit, ":")) != NULL) {
+		len = strlen(path);
+
+		/* strip the trailing slash if one exists */
+		while(path[len - 1] == '/') {
+				path[--len] = '\0';
+		}
+
+		snprintf(fullname, sizeof(fullname), "%s/%s", path, filename);
+
+		if(stat(fullname, bufptr) == 0) {
+			strncpy(filename, fullname, size);
+			free(envpath);
+			return(0);
+		}
+	}
+	free(envpath);
+	return(-1);
+}
+
 static int query_fileowner(alpm_list_t *targets)
 {
 	int ret = 0;
 	alpm_list_t *t;
+	size_t len=PATH_MAX+1;
 
 	/* This code is here for safety only */
 	if(targets == NULL) {
@@ -67,19 +101,31 @@ static int query_fileowner(alpm_list_t *targets)
 		return(1);
 	}
 
+	char *filename = calloc(len, sizeof(char));
+
 	for(t = targets; t; t = alpm_list_next(t)) {
 		int found = 0;
-		char *filename = alpm_list_getdata(t);
+		strncpy(filename, alpm_list_getdata(t), len);
 		char *bname, *dname, *rpath;
 		const char *root;
 		struct stat buf;
 		alpm_list_t *i, *j;
 
 		if(lstat(filename, &buf) == -1) {
-			pm_fprintf(stderr, PM_LOG_ERROR, _("failed to read file '%s': %s\n"),
-					filename, strerror(errno));
-			ret++;
-			continue;
+			/*  if it is not a path but a program name, then check in PATH */
+			if(strchr(filename, '/') == NULL) {
+				if(search_path(filename, len, &buf) == -1) {
+					pm_fprintf(stderr, PM_LOG_ERROR, _("failed to read file '%s': %s\n"),
+						filename, strerror(errno));
+					ret++;
+					continue;
+				}
+			} else {
+				pm_fprintf(stderr, PM_LOG_ERROR, _("failed to read file '%s': %s\n"),
+						filename, strerror(errno));
+				ret++;
+				continue;
+			}
 		}
 
 		if(S_ISDIR(buf.st_mode)) {
@@ -140,6 +186,7 @@ static int query_fileowner(alpm_list_t *targets)
 		free(rpath);
 	}
 
+	free(filename);
 	return ret;
 }
 
-- 
1.7.0.1