Add support for io-plugin initialization via null system command =! (#14915) ##io

* Useful for r2frida to automatically run .=!i*

libr/core/cfile.c

@@ -857,7 +857,6 @@ R_API RCoreFile *r_core_file_open(RCore *r, const char *file, int flags, ut64 lo
 	fh->alive = 1;
 	fh->core = r;
 	fh->fd = fd->fd;
-
 	{
 		const char *cp = r_config_get (r->config, "cmd.open");
 		if (cp && *cp) {
@@ -890,6 +889,7 @@ R_API RCoreFile *r_core_file_open(RCore *r, const char *file, int flags, ut64 lo
 	if (loadaddr != UT64_MAX) {
 		r_config_set_i (r->config, "bin.laddr", loadaddr);
 	}
+	r_core_cmd0 (r, "=!");
 beach:
 	r->times->file_open_time = r_sys_now () - prev;
 	return fh;

libr/core/visual.c

@@ -1530,6 +1530,9 @@ repeat:
 	} else if (ch == 'G') {
 		skip = 9999;
 		goto repeat;
+	} else if (ch == '/') {
+		r_core_cmd0 (core, "?i highlight;e scr.highlight=`yp`");
+		goto repeat;
 	} else if (ch == ';') {
 		addComment (core, cur_ref_addr);
 		goto repeat;

libr/io/p/io_gdb.c

@@ -216,7 +216,10 @@ static char *__system(RIO *io, RIODesc *fd, const char *cmd) {
 	if (!desc) {
 		return NULL;
 	}
-	if (!cmd[0] || cmd[0] == '?' || !strcmp (cmd, "help")) {
+	if (!*cmd) {
+		return NULL;
+	}
+	if (cmd[0] == '?' || !strcmp (cmd, "help")) {
 		eprintf ("Usage: =!cmd args\n"
 			 " =!pid             - show targeted pid\n"
 			 " =!pkt s           - send packet 's'\n"

libr/io/p/io_mach.c

@@ -489,6 +489,9 @@ static char *__system(RIO *io, RIODesc *fd, const char *cmd) {
 
 	task_t task = pid_to_task (fd, iodd->tid);
 	/* XXX ugly hack for testing purposes */
+	if (!strcmp (cmd, "")) {
+		return NULL;
+	}
 	if (!strncmp (cmd, "perm", 4)) {
 		int perm = r_str_rwx (cmd + 4);
 		if (perm) {

libr/io/p/io_ptrace.c

@@ -258,6 +258,9 @@ static char *__system(RIO *io, RIODesc *fd, const char *cmd) {
 	RIOPtrace *iop = (RIOPtrace*)fd->data;
 	//printf("ptrace io command (%s)\n", cmd);
 	/* XXX ugly hack for testing purposes */
+	if (!strcmp (cmd, "")) {
+		return NULL;
+	}
 	if (!strcmp (cmd, "help")) {
 		eprintf ("Usage: =!cmd args\n"
 			" =!ptrace   - use ptrace io\n"

libr/io/p/io_r2k.c

@@ -84,6 +84,9 @@ static bool r2k__plugin_open(RIO *io, const char *pathname, bool many) {
 }
 
 static char *r2k__system(RIO *io, RIODesc *fd, const char *cmd) {
+	if (!strcmp (cmd, "")) {
+		return NULL;
+	}
 	if (!strncmp (cmd, "mod", 3)) {
 #if __WINDOWS__
 		GetSystemModules (io);

libr/io/p/io_r2web.c

@@ -135,6 +135,9 @@ static RIODesc *__open(RIO *io, const char *pathname, int rw, int mode) {
 }
 
 static char *__system(RIO *io, RIODesc *fd, const char *command) {
+	if (!*command) {
+		return NULL;
+	}
 	int code, rlen;
 	char *cmd = r_str_uri_encode (command);
 	char *url = r_str_newf ("%s/%s", rURL(fd), cmd);

libr/io/p/io_w32dbg.c

@@ -175,7 +175,9 @@ static char *__system(RIO *io, RIODesc *fd, const char *cmd) {
 	RIOW32Dbg *iop = fd->data;
 	//printf("w32dbg io command (%s)\n", cmd);
 	/* XXX ugly hack for testing purposes */
-	if (!strncmp (cmd, "pid", 3)) {
+	if (!strcmp (cmd, "")) {
+		// do nothing
+	} else if (!strncmp (cmd, "pid", 3)) {
 		if (cmd[3] == ' ') {
 			int pid = atoi (cmd + 3);
 			if (pid > 0 && pid != iop->pi.dwProcessId) {

libr/io/p/io_winedbg.c

@@ -224,6 +224,9 @@ static struct winedbg_x86_32 regState() {
 }
 
 static char *__system(RIO *io, RIODesc *fd, const char *cmd) {
+	if (!strcmp (cmd, "")) {
+		return NULL;
+	}
 	if (!strncmp (cmd, "?", 1)) {
 		eprintf ("dr  : show registers\n");
 		eprintf ("dr* : show registers as flags\n");

libr/main/radare2.c

@@ -1257,6 +1257,7 @@ R_API int r_main_radare2(int argc, char **argv) {
 			const char *fstype = r.bin->cur->o->info->bclass;
 			r_core_cmdf (&r, "m /root %s @ 0", fstype);
 		}
+		r_core_cmd0 (&r, "=!"); // initalize io subsystem
 		iod = r.io ? r_io_desc_get (r.io, fh->fd) : NULL;
 #if USE_THREADS
 		if (iod && load_bin == LOAD_BIN_ALL && threaded) {