1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23 24 #include <ctype.h> 25 #include <errno.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 30 int main() { 31 for (;;) { 32 int c; 33 errno = 0; 34 c = getchar(); 35 if (c == EOF) { 36 exit(errno == 0 ? EXIT_SUCCESS : EXIT_FAILURE); 37 } else if (isalnum(c) || strchr("!$'()*+,-.:=@_~/\n", c) != NULL) { 38 /* valid RFC 2396 pchar characters + '/' + newline */ 39 if (putchar(c) == EOF) { 40 exit(EXIT_FAILURE); 41 } 42 } else if (printf("%%%02X", (unsigned char) (char) c) < 0) { 43 exit(EXIT_FAILURE); 44 } 45 } 46 } 47