clean up buffer, and add function to run install script

1 files changed, 75 insertions, 22 deletions

diff --git a/snag/pkg_db.c b/snag/pkg_db.c
index ad9eff3..032c089 100644
--- a/snag/pkg_db.c
+++ b/snag/pkg_db.c
@@ -8,23 +8,26 @@
 #include <errno.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"
+#define PKG_INST_CMD "./run_pkg_install.sh"
 
-bool load_package_info(package_info_t* info, char* pkgid) {
+// note: fixed location of package database for now
+const char pkg_db[] = "../packages"; 
+const size_t pkg_db_len = sizeof(pkg_db) - 1;
+
+bool load_package_info(char* pkgid, package_info_t* info) {
 
     memset(info, 0, sizeof(*info));
     size_t pkgid_len = strlen(pkgid);
 
 	// construct package description directory path and ensure it exists
-    // pkg_dir = "PKG_DB/pkgid"
-	size_t pkg_dir_len = PKG_DB_LEN + pkgid_len + 1;
+    // pkg_dir = "pkg_db/pkgid"
+	size_t pkg_dir_len = pkg_db_len + pkgid_len + 1;
 	char* pkg_dir = emalloc(pkg_dir_len + 1, "pkg_dir");
 	{
-		memcpy(pkg_dir, PKG_DB, PKG_DB_LEN);
-		pkg_dir[PKG_DB_LEN] = '/';
-		memcpy(pkg_dir + PKG_DB_LEN + 1, pkgid, pkgid_len);
+		memcpy(pkg_dir, pkg_db, pkg_db_len);
+		pkg_dir[pkg_db_len] = '/';
+		memcpy(pkg_dir + pkg_db_len + 1, pkgid, pkgid_len);
 		pkg_dir[pkg_dir_len] = '\0';
 		if (access(pkg_dir, F_OK) != 0) {
 			eprintf("Package '%s' not found\n", pkgid);
@@ -41,7 +44,8 @@ bool load_package_info(package_info_t* info, char* pkgid) {
 		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);
+		memcpy(&info->script_path[script_path_len - 3], ".sh", 3);
+		info->script_path[script_path_len] = '\0';
 		free(pkg_dir);
 		if (access(info->script_path, F_OK) != 0) {
 			eprintf("Package '%s' broken, doesn't have description script\n", pkgid);
@@ -50,15 +54,15 @@ bool load_package_info(package_info_t* info, char* pkgid) {
 		}
 	}
 
-	// PIPE and FORK to run get pkg attrs script
+	// PIPE and FORK to run pkg attrs script
     int pipefds[2] = {0};
     if (pipe(pipefds) < 0) error_out("failed to pipe: %s", strerror(errno));
     pid_t pid = fork();
     if (pid < 0) error_out("failed to fork: %s", strerror(errno));
 
-	// child proc
     if (pid == 0) {
-		// write my stdout the the pipe
+		// child proc
+		// write my stdout to the pipe
         close(pipefds[0]);
         dup2(pipefds[1], STDOUT_FILENO);
         close(pipefds[1]);
@@ -66,36 +70,85 @@ bool load_package_info(package_info_t* info, char* pkgid) {
         char* argv[] = { PKG_INFO_CMD, info->script_path, NULL };
         char* envp[] = { NULL };
         execve(PKG_INFO_CMD, argv, envp);
+		// what are you still doing here?
 		error_out("execve failed");
-    }
+    } else {
+		// parent proc, close write end of pipe
+		close(pipefds[1]);
+	}
 
 	// wait for child to finish
     int wstatus;
     if (waitpid(pid, &wstatus, 0) < 0) error_out("waitpid failed: %s", strerror(errno));
 	if (WEXITSTATUS(wstatus) != 0) error_out("failed to execute get pkg attr script");
 
-	// read all bytes from pipe
-    ssize_t bytes_read = read(pipefds[0], info->package_attrs, sizeof(info->package_attrs));
-    if (bytes_read < 0) error_out("Failed to read from pipe");
+	// read all bytes from pipe into attr buffer
+    ssize_t bytes_read = read(pipefds[0], info->attrs.buffer, sizeof(info->attrs.buffer));
+    if (bytes_read < 0) error_out("failed to read from pipe: %s", strerror(errno));
+	close(pipefds[0]);
 
-	// read attributes from pipe data
+	// read attributes from attr buffer
+	// attribute format: type (char), data value (null terminated str)
+	// todo(jqj): switch over to dynamically allocated buffer
     for (int i = 0; i < bytes_read;) {
-        char atype = info->package_attrs[i];
+        char atype = info->attrs.buffer[i];
         i++;
         switch (atype) {
         case 'i':
-            info->attrs.id = &info->package_attrs[i];
+            info->attrs.id = &info->attrs.buffer[i];
             break;
         case 'n':
-            info->attrs.name = &info->package_attrs[i];
+            info->attrs.name = &info->attrs.buffer[i];
             break;
         case 'd':
-            info->attrs.desc = &info->package_attrs[i];
+            info->attrs.desc = &info->attrs.buffer[i];
             break;
         }
-        for(;info->package_attrs[i] && i < bytes_read; i++);
+        for(;info->attrs.buffer[i] && i < bytes_read; i++);
         i++;
     }
 
 	return true;
 }
+
+void run_package_install(const package_info_t* info) {
+
+	// PIPE and FORK to run install script
+    int pipefds[2] = {0};
+    if (pipe(pipefds) < 0) error_out("failed to pipe: %s", strerror(errno));
+    pid_t pid = fork();
+    if (pid < 0) error_out("failed to fork: %s", strerror(errno));
+
+    if (pid == 0) {
+		// child proc
+		// write my stdout and stderr to the pipe
+        close(pipefds[0]);
+        dup2(pipefds[1], STDOUT_FILENO);
+        dup2(pipefds[1], STDERR_FILENO);
+        close(pipefds[1]);
+		// exec into install script
+        char* argv[] = { PKG_INST_CMD, info->script_path, NULL };
+        char* envp[] = { NULL };
+        execve(PKG_INST_CMD, argv, envp);
+		// what are you still doing here?
+		error_out("execve failed");
+    } else {
+		// parent proc, close write end of pipe
+		close(pipefds[1]);
+	}
+
+	// read from the pipe until EOF
+	char buf[4096];
+	ssize_t bytes_read = 0;
+    while ((bytes_read = read(pipefds[0], buf, sizeof(buf))) > 0) {
+		// print build out, can log and stuff in future
+		printf("%.*s", (int)bytes_read, buf);
+	}
+    if (bytes_read < 0) error_out("failed to read from pipe: %s", strerror(errno));
+	close(pipefds[0]);
+
+	// reap the child to finish
+    int wstatus;
+    if (waitpid(pid, &wstatus, 0) < 0) error_out("waitpid failed: %s", strerror(errno));
+	if (WEXITSTATUS(wstatus) != 0) error_out("failed to execute install script");
+}