remove popen because its not cool

1 files changed, 80 insertions, 48 deletions

diff --git a/snag/pkg_db.c b/snag/pkg_db.c
index 26e972d..ee11288 100644
--- a/snag/pkg_db.c
+++ b/snag/pkg_db.c
@@ -4,26 +4,46 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/wait.h>
 
 #define PKG_DB "../packages"
+#define PKG_DB_LEN (sizeof(PKG_DB) - 1)
 #define PKG_INFO_CMD "./get_pkg_attrs.sh"
 
 bool load_package_info(package_info_t* info, char* pkgid) {
+    memset(info, 0, sizeof(*info));
 
 	// construct package description directory path and ensure it exists
-	size_t pkg_dir_len = strlen(PKG_DB) + strlen(pkgid) + 1;
+    size_t pkgid_len = strlen(pkgid);
+	size_t pkg_dir_len = PKG_DB_LEN + pkgid_len + 1;
 	char* pkg_dir = malloc(pkg_dir_len + 1);
-	snprintf(pkg_dir, pkg_dir_len + 1, "%s/%s", PKG_DB, pkgid);
+    if (!pkg_dir) {
+        fprintf(stderr, "Failed to alloc pkg_dir\n");
+        exit(1);
+    }
+    // pkg_dir = "PKG_DB/pkgid"
+    memcpy(pkg_dir, PKG_DB, PKG_DB_LEN);
+    pkg_dir[PKG_DB_LEN] = '/';
+    memcpy(&pkg_dir[PKG_DB_LEN + 1], pkgid, pkgid_len + 1);
+
 	if (access(pkg_dir, F_OK) != 0) {
-        fprintf(stderr, "Package '%s' not found in database\n", pkgid);
-		free(pkg_dir);
-		return false;
+        fprintf(stderr, "Package '%s' not found\n", pkgid);
+        free(pkg_dir);
+        return false;
     }
 
 	// construct package description script path and ensure it exists
-	size_t script_path_len = pkg_dir_len + strlen(pkgid) + 4;
+	size_t script_path_len = pkg_dir_len + pkgid_len + 4;
 	info->script_path = malloc(script_path_len + 1);
-	snprintf(info->script_path, script_path_len + 1, "%s/%s.sh", pkg_dir, pkgid);
+    if (!info->script_path) {
+        fprintf(stderr, "Failed to alloc info->script_path\n");
+        exit(1);
+    }
+
+    memcpy(info->script_path, pkg_dir, pkg_dir_len);
+    info->script_path[pkg_dir_len] = '/';
+    memcpy(&info->script_path[pkg_dir_len + 1], pkgid, pkgid_len);
+    memcpy(&info->script_path[script_path_len - 3], ".sh", 4);
 	free(pkg_dir);
 	if (access(info->script_path, F_OK) != 0) {
         fprintf(stderr, "Package '%s' broken, doesn't have description script\n", pkgid);
@@ -31,51 +51,63 @@ bool load_package_info(package_info_t* info, char* pkgid) {
 		return false;
     }
 
-	// construct get_pkg_attrs script cmd and invoke it
-	size_t cmd_len = strlen(PKG_INFO_CMD) + script_path_len + 3;
-	char* cmd = malloc(cmd_len + 1);
-	snprintf(cmd, cmd_len + 1, "%s '%s'", PKG_INFO_CMD, info->script_path);
-	FILE* getinfo_fp = popen(cmd, "r");
-	free(cmd);
-	if (getinfo_fp == NULL) {
-        perror("failed to popen get_pkg_attrs");
-		exit(1); // fatal error
+    int pipefds[2] = {0};
+    if (pipe(pipefds) < 0) {
+        fprintf(stderr, "Failed to create pipe\n");
+        exit(1);
+    }
+    pid_t pid = fork();
+    if (pid < 0) {
+        fprintf(stderr, "Failed to create child process\n");
+        exit(1);
+    }
+
+    if (pid == 0) {
+        close(pipefds[0]);
+        dup2(pipefds[1], STDOUT_FILENO);
+        close(pipefds[1]);
+
+        char* argv[] = { PKG_INFO_CMD, info->script_path, NULL };
+        char* envp[] = { NULL };
+        execve(PKG_INFO_CMD, argv, envp);
+        fprintf(stderr, "execve failed\n");
+        exit(127);
     }
 
-	// go through each NULL delimited section of the output (attributes)
-	size_t n = 0;
-	char* line = NULL;
-	ssize_t read;
-	while ((read = getdelim(&line, &n, '\0', getinfo_fp)) != -1) {
-		// read in property based on first attribute type character
-		char  atype  = line[0];
-		char* avalue = line+1;
-		switch (atype) {
-			case 'i':
-				// id
-				info->id = strdup(avalue);
-				break;
-			case 'n':
-				// name
-				info->name = strdup(avalue);
-				break;
-			case 'd':
-				// description
-				info->desc = strdup(avalue);
-				break;
-		}
+    int wstatus;
+    if (waitpid(pid, &wstatus, 0) < 0) {
+        fprintf(stderr, "waitpid failed\n");
+        exit(1);
+    }
+    if (WEXITSTATUS(wstatus) == 127) {
+        exit(1);
     }
-	free(line);
 
-	// close the get_pkg_attrs process
-	int close_err = pclose(getinfo_fp);
-	if (close_err == -1) {
-        perror("failed to pclose get_pkg_attrs");
-		exit(1); // fatal error
-	} else if (close_err != 0) {
-		fprintf(stderr, "failed to execute get_pkg_attrs: %d\n", close_err);
-		exit(1); // fatal error
-	}
+    ssize_t bytes_read = read(pipefds[0], info->package_attrs, sizeof(info->package_attrs));
+    if (bytes_read < 0) {
+        fprintf(stderr, "Failed to read from pipe\n");
+        exit(1);
+    }
+
+    free(info->script_path);
+
+    for (int i = 0; i < bytes_read;) {
+        char atype = info->package_attrs[i];
+        i++;
+        switch (atype) {
+        case 'i':
+            info->attrs.id = &info->package_attrs[i];
+            break;
+        case 'n':
+            info->attrs.name = &info->package_attrs[i];
+            break;
+        case 'd':
+            info->attrs.desc = &info->package_attrs[i];
+            break;
+        }
+        for(;info->package_attrs[i] && i < bytes_read; i++);
+        i++;
+    }
 
 	return true;
 }