diff --git a/tests/sm4test.c b/tests/sm4test.c
index 6e6dda36..4776c30d 100644
--- a/tests/sm4test.c
+++ b/tests/sm4test.c
@@ -168,9 +168,8 @@ static int test_sm4_ctr32_encrypt_blocks(void)
 	sm4_set_encrypt_key(&sm4_key, key);
 	sm4_ctr32_encrypt_blocks(&sm4_key, ctr, plaintext, 4, encrypted);
 
-	format_bytes(stderr, 0, 0, "sm4_ctr32", encrypted, 64);
-
 	/*
+	// FIXME: relace the corrent ciphertext
 	if (memcmp(encrypted, ciphertext, sizeof(ciphertext)) != 0) {
 		error_print();
 		return -1;
diff --git a/tests/sm9test.c b/tests/sm9test.c
index 4177aa62..abcf2bb6 100644
--- a/tests/sm9test.c
+++ b/tests/sm9test.c
@@ -819,7 +819,7 @@ int test_sm9_z256_exchange()
 
 	for (i = 0; i < klen; i++) {
 		if (skA[i] != skB[i]) {
-			printf("Exchange key different at byte %d\n", i);
+			printf("Exchange key different at byte %zu\n", i);
 			goto err;
 		}
 	} ++j;
@@ -827,7 +827,7 @@ int test_sm9_z256_exchange()
 	printf("%s() ok\n", __FUNCTION__);
 	return 1;
 err:
-	printf("%s test %d failed\n", __FUNCTION__, j);
+	printf("%s test %zu failed\n", __FUNCTION__, j);
 	error_print();
 	return -1;
 }
diff --git a/tools/sm4_cbc.c b/tools/sm4_cbc.c
index 3919a11b..a4d6c73c 100755
--- a/tools/sm4_cbc.c
+++ b/tools/sm4_cbc.c
@@ -21,6 +21,7 @@
 static const char *usage = "{-encrypt|-decrypt} -key hex -iv hex [-in file] [-out file]";
 
 static const char *options =
+"\n"
 "Options\n"
 "\n"
 "    -encrypt            Encrypt\n"
@@ -30,9 +31,13 @@ static const char *options =
 "    -in file | stdin    Input data\n"
 "    -out file | stdout  Output data\n"
 "\n"
-"Examples"
+"Examples\n"
 "\n"
-"  echo \"hello\" | gmssl sm4_cbc -encrypt -key 11223344556677881122334455667788 -iv 112233445566778811223344 -out ciphertext.bin\n"
+"  $ TEXT=`gmssl rand -outlen 20 -hex`\n"
+"  $ KEY=`gmssl rand -outlen 16 -hex`\n"
+"  $ IV=`gmssl rand -outlen 16 -hex`\n"
+"  $ echo -n $TEXT | gmssl sm4_cbc -encrypt -key $KEY -iv $IV -out sm4_cbc_ciphertext.bin\n"
+"  $ gmssl sm4_cbc -decrypt -key $KEY -iv $IV -in sm4_cbc_ciphertext.bin\n"
 "\n";
 
 int sm4_cbc_main(int argc, char **argv)
diff --git a/tools/sm4_cfb.c b/tools/sm4_cfb.c
index 463a6fff..a8e18212 100755
--- a/tools/sm4_cfb.c
+++ b/tools/sm4_cfb.c
@@ -21,6 +21,7 @@
 static const char *usage = "{-encrypt|-decrypt} -key hex -iv hex [-in file] [-out file]";
 
 static const char *options =
+"\n"
 "Options\n"
 "\n"
 "    -encrypt            Encrypt\n"
@@ -30,9 +31,13 @@ static const char *options =
 "    -in file | stdin    Input data\n"
 "    -out file | stdout  Output data\n"
 "\n"
-"Examples"
+"Examples\n"
 "\n"
-"  echo \"hello\" | gmssl sm4_cfb -encrypt -key 11223344556677881122334455667788 -iv 112233445566778811223344 -out ciphertext.bin\n"
+"  $ TEXT=`gmssl rand -outlen 20 -hex`\n"
+"  $ KEY=`gmssl rand -outlen 16 -hex`\n"
+"  $ IV=`gmssl rand -outlen 16 -hex`\n"
+"  $ echo -n $TEXT | gmssl sm4_cfb -encrypt -key $KEY -iv $IV -out sm4_cfb_ciphertext.bin\n"
+"  $ gmssl sm4_cfb -decrypt -key $KEY -iv $IV -in sm4_cfb_ciphertext.bin\n"
 "\n";
 
 int sm4_cfb_main(int argc, char **argv)
diff --git a/tools/sm4_ctr.c b/tools/sm4_ctr.c
index 9684e747..2841e114 100755
--- a/tools/sm4_ctr.c
+++ b/tools/sm4_ctr.c
@@ -21,6 +21,7 @@
 static const char *usage = "[-encrypt|-decrypt] -key hex -iv hex [-in file] [-out file]";
 
 static const char *options =
+"\n"
 "Options\n"
 "\n"
 "    -encrypt            Encrypt\n"
@@ -30,9 +31,13 @@ static const char *options =
 "    -in file | stdin    Input data\n"
 "    -out file | stdout  Output data\n"
 "\n"
-"Examples"
+"Examples\n"
 "\n"
-"  echo \"hello\" | gmssl sm4_ctr -key 11223344556677881122334455667788 -iv 112233445566778811223344 -out ciphertext.bin\n"
+"  $ TEXT=`gmssl rand -outlen 20 -hex`\n"
+"  $ KEY=`gmssl rand -outlen 16 -hex`\n"
+"  $ IV=`gmssl rand -outlen 16 -hex`\n"
+"  $ echo -n $TEXT | gmssl sm4_ctr -key $KEY -iv $IV -out sm4_ctr_ciphertext.bin\n"
+"  $ gmssl sm4_ctr -key $KEY -iv $IV -in sm4_ctr_ciphertext.bin\n"
 "\n";
 
 int sm4_ctr_main(int argc, char **argv)
diff --git a/tools/sm4_ecb.c b/tools/sm4_ecb.c
index 68b596b3..4f556c39 100755
--- a/tools/sm4_ecb.c
+++ b/tools/sm4_ecb.c
@@ -21,6 +21,7 @@
 static const char *usage = "{-encrypt|-decrypt} -key hex [-in file] [-out file]";
 
 static const char *options =
+"\n"
 "Options\n"
 "\n"
 "    -encrypt            Encrypt\n"
@@ -29,9 +30,12 @@ static const char *options =
 "    -in file | stdin    Input data\n"
 "    -out file | stdout  Output data\n"
 "\n"
-"Examples"
+"Examples\n"
 "\n"
-"  echo \"hello\" | gmssl sm4_ecb -encrypt -key 11223344556677881122334455667788 -iv 112233445566778811223344 -out ciphertext.bin\n"
+"  $ TEXT=`gmssl rand -outlen 32 -hex`\n"
+"  $ KEY=`gmssl rand -outlen 16 -hex`\n"
+"  $ echo -n $TEXT | gmssl sm4_ecb -encrypt -key $KEY -out sm4_ecb_ciphertext.bin\n"
+"  $ gmssl sm4_ecb -decrypt -key $KEY -in sm4_ecb_ciphertext.bin\n"
 "\n";
 
 int sm4_ecb_main(int argc, char **argv)
@@ -40,7 +44,6 @@ int sm4_ecb_main(int argc, char **argv)
 	char *prog = argv[0];
 	int enc = -1;
 	char *keyhex = NULL;
-	char *ivhex = NULL;
 	char *infile = NULL;
 	char *outfile = NULL;
 	uint8_t key[16];
@@ -123,10 +126,6 @@ bad:
 		fprintf(stderr, "gmssl %s: option `-key` missing\n", prog);
 		goto end;
 	}
-	if (!ivhex) {
-		fprintf(stderr, "gmssl %s: option `-iv` missing\n", prog);
-		goto end;
-	}
 
 	if (enc) {
 		if (sm4_ecb_encrypt_init(&ctx, key) != 1) {
diff --git a/tools/sm4_gcm.c b/tools/sm4_gcm.c
index 6756e968..0de436bc 100755
--- a/tools/sm4_gcm.c
+++ b/tools/sm4_gcm.c
@@ -33,10 +33,14 @@ static const char *options =
 "    -in file | stdin    Input data\n"
 "    -out file | stdout  Output data\n"
 "\n"
-"Examples"
+"Examples\n"
 "\n"
-"  echo \"hello\" | gmssl sm4_gcm -encrypt -key 11223344556677881122334455667788 -iv 112233445566778811223344 -out ciphertext.bin\n"
-"  gmssl sm4_gcm -decrypt -key 11223344556677881122334455667788 -iv 112233445566778811223344 -in ciphertext.bin\n"
+"  $ TEXT=`gmssl rand -outlen 20 -hex`\n"
+"  $ KEY=`gmssl rand -outlen 16 -hex`\n"
+"  $ IV=`gmssl rand -outlen 12 -hex`\n"
+"  $ AAD=\"The AAD Data\"\n"
+"  $ echo -n $TEXT | gmssl sm4_gcm -encrypt -key $KEY -iv $IV -aad $AAD -out sm4_gcm_ciphertext.bin\n"
+"  $ gmssl sm4_gcm -decrypt -key $KEY -iv $IV -in sm4_gcm_ciphertext.bin\n"
 "\n";
 
 int sm4_gcm_main(int argc, char **argv)
diff --git a/tools/sm4_ofb.c b/tools/sm4_ofb.c
index 210d5fa2..65a1dc83 100755
--- a/tools/sm4_ofb.c
+++ b/tools/sm4_ofb.c
@@ -21,6 +21,7 @@
 static const char *usage = "[-encrypt|-decrypt] -key hex -iv hex [-in file] [-out file]";
 
 static const char *options =
+"\n"
 "Options\n"
 "\n"
 "    -encrypt            Encrypt\n"
@@ -30,9 +31,13 @@ static const char *options =
 "    -in file | stdin    Input data\n"
 "    -out file | stdout  Output data\n"
 "\n"
-"Examples"
+"Examples\n"
 "\n"
-"  echo \"hello\" | gmssl sm4_ofb -key 11223344556677881122334455667788 -iv 112233445566778811223344 -out ciphertext.bin\n"
+"  $ TEXT=`gmssl rand -outlen 32 -hex`\n"
+"  $ KEY=`gmssl rand -outlen 16 -hex`\n"
+"  $ IV=`gmssl rand -outlen 16 -hex`\n"
+"  $ echo -n $TEXT | gmssl sm4_ofb -encrypt -key $KEY -iv $IV -out sm4_ofb_ciphertext.bin\n"
+"  $ gmssl sm4_ofb -decrypt -key $KEY -iv $IV -in sm4_ofb_ciphertext.bin\n"
 "\n";
 
 int sm4_ofb_main(int argc, char **argv)