Fix #16210 - Show error message and update help for we ##io

libr/core/cio.c

@@ -424,7 +424,7 @@ R_API bool r_core_write_at(RCore *core, ut64 addr, const ut8 *buf, int size) {
 	return ret;
 }
 
-R_API int r_core_extend_at(RCore *core, ut64 addr, int size) {
+R_API bool r_core_extend_at(RCore *core, ut64 addr, int size) {
 	int ret;
 	if (!core->io || !core->file || size < 1) {
 		return false;

libr/core/cmd.c

@@ -2884,7 +2884,7 @@ static int r_core_cmd_subst_i(RCore *core, char *cmd, char *colon, bool *tmpseek
 			line = strdup (cmd);
 			line = r_str_replace (line, "\\\"", "\"", true);
 			if (p && *p && p[1] == '|') {
-				str = r_str_trim_head_ro (p + 2);
+				str = (char *)r_str_trim_head_ro (p + 2);
 				r_core_cmd_pipe (core, cmd, str);
 			} else {
 				r_cmd_call (core->rcmd, line);

libr/core/cmd_write.c

@@ -1,4 +1,4 @@
-/* radare - LGPL - Copyright 2009-2019 - pancake */
+/* radare - LGPL - Copyright 2009-2020 - pancake */
 
 #include "r_crypto.h"
 #include "r_config.h"
@@ -80,12 +80,12 @@ static const char *help_msg_wc[] = {
 };
 
 static const char *help_msg_we[] = {
-	"Usage", "", "write extend",
-	"wen", " <num>", "insert num null bytes at current offset",
-	"weN", " <addr> <len>", "insert bytes at address",
+	"Usage", "", "write extend # resize the file",
+	"wen", " <num>", "extend the underlying file inserting NUM null bytes at current offset",
+	"weN", " <addr> <len>", "extend current file and insert bytes at address",
 	"wes", " <addr>  <dist> <block_size>", "shift a blocksize left or write in the editor",
-	"wex", " <hex_bytes>", "insert bytes at current offset",
-	"weX", " <addr> <hex_bytes>", "insert bytes at address",
+	"wex", " <hex_bytes>", "insert bytes at current offset by extending the file",
+	"weX", " <addr> <hex_bytes>", "insert bytes at address by extending the file",
 	NULL
 };
 
@@ -879,12 +879,16 @@ static int cmd_write(void *data, const char *input) {
 		switch (input[1]) {
 		case 'n': // "wen"
 			if (input[2] == ' ') {
-				len = *input ? r_num_math (core->num, input+3) : 0;
+				len = *input ? r_num_math (core->num, input+ 3) : 0;
 				if (len > 0) {
 					const ut64 cur_off = core->offset;
 					cmd_suc = r_core_extend_at (core, core->offset, len);
-					core->offset = cur_off;
-					r_core_block_read (core);
+					if (cmd_suc) {
+						core->offset = cur_off;
+						r_core_block_read (core);
+					} else {
+						eprintf ("r_io_extend failed\n");
+					}
 				}
 			}
 			break;
@@ -899,9 +903,13 @@ static int cmd_write(void *data, const char *input) {
 				if (len > 0){
 					ut64 cur_off = core->offset;
 					cmd_suc = r_core_extend_at (core, addr, len);
-					r_core_seek (core, cur_off, 1);
-					core->offset = addr;
-					r_core_block_read (core);
+					if (cmd_suc) {
+						r_core_seek (core, cur_off, 1);
+						core->offset = addr;
+						r_core_block_read (core);
+					} else {
+						eprintf ("r_io_extend failed\n");
+					}
 				}
 				cmd_suc = true;
 			}
@@ -970,6 +978,8 @@ static int cmd_write(void *data, const char *input) {
 						if (!r_core_write_at (core, addr, bytes, len)) {
 							cmd_write_fail (core);
 						}
+					} else {
+						eprintf ("r_io_extend failed\n");
 					}
 					core->offset = addr;
 					r_core_block_read (core);

libr/include/r_core.h

@@ -507,7 +507,7 @@ R_API int r_core_file_list(RCore *core, int mode);
 R_API int r_core_file_binlist(RCore *core);
 R_API bool r_core_file_bin_raise(RCore *core, ut32 num);
 R_API int r_core_seek_delta(RCore *core, st64 addr);
-R_API int r_core_extend_at(RCore *core, ut64 addr, int size);
+R_API bool r_core_extend_at(RCore *core, ut64 addr, int size);
 R_API bool r_core_write_at(RCore *core, ut64 addr, const ut8 *buf, int size);
 R_API int r_core_write_op(RCore *core, const char *arg, char op);
 R_API ut8* r_core_transform_op(RCore *core, const char *arg, char op);