1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "command.h" 18 19 #include "print.h" 20 #include "util.h" 21 22 #include <errno.h> 23 #include <string.h> 24 #include <stdlib.h> 25 #include <sys/types.h> 26 #include <sys/stat.h> 27 #include <unistd.h> 28 #include <sys/wait.h> 29 30 extern char **environ; 31 32 Command::Command(const string& prog) 33 :prog(prog) 34 { 35 } 36 37 Command::~Command() 38 { 39 } 40 41 void 42 Command::AddArg(const string& arg) 43 { 44 args.push_back(arg); 45 } 46 47 void 48 Command::AddEnv(const string& name, const string& value) 49 { 50 env[name] = value; 51 } 52 53 const char* 54 Command::GetProg() const 55 { 56 return prog.c_str(); 57 } 58 59 char *const * 60 Command::GetArgv() const 61 { 62 const int N = args.size(); 63 char** result = (char**)malloc(sizeof(char*)*(N+2)); 64 result[0] = strdup(prog.c_str()); 65 for (int i=0; i<N; i++) { 66 result[i+1] = strdup(args[i].c_str()); 67 } 68 result[N+1] = 0; 69 return result; 70 } 71 72 char *const * 73 Command::GetEnv() const 74 { 75 map<string,string> copy; 76 for (const char** p=(const char**)environ; *p != NULL; p++) { 77 char* name = strdup(*p); 78 char* value = strchr(name, '='); 79 *value = '\0'; 80 value++; 81 copy[name] = value; 82 free(name); 83 } 84 for (map<string,string>::const_iterator it=env.begin(); it!=env.end(); it++) { 85 copy[it->first] = it->second; 86 } 87 char** result = (char**)malloc(sizeof(char*)*(copy.size()+1)); 88 char** row = result; 89 for (map<string,string>::const_iterator it=copy.begin(); it!=copy.end(); it++) { 90 *row = (char*)malloc(it->first.size() + it->second.size() + 2); 91 strcpy(*row, it->first.c_str()); 92 strcat(*row, "="); 93 strcat(*row, it->second.c_str()); 94 row++; 95 } 96 *row = NULL; 97 return result; 98 } 99 100 string 101 get_command_output(const Command& command, int* err, bool quiet) 102 { 103 if (!quiet) { 104 print_command(command); 105 } 106 107 int fds[2]; 108 if (0 != pipe(fds)) { 109 return string(); 110 } 111 112 pid_t pid = fork(); 113 114 if (pid == -1) { 115 // fork error 116 *err = errno; 117 return string(); 118 } else if (pid == 0) { 119 // child 120 while ((dup2(fds[1], STDOUT_FILENO) == -1) && (errno == EINTR)) {} 121 close(fds[1]); 122 close(fds[0]); 123 const char* prog = command.GetProg(); 124 char* const* argv = command.GetArgv(); 125 char* const* env = command.GetEnv(); 126 exec_with_path_search(prog, argv, env); 127 if (!quiet) { 128 print_error("Unable to run command: %s", prog); 129 } 130 exit(1); 131 } else { 132 // parent 133 close(fds[1]); 134 string result; 135 const int size = 16*1024; 136 char* buf = (char*)malloc(size); 137 while (true) { 138 ssize_t amt = read(fds[0], buf, size); 139 if (amt <= 0) { 140 break; 141 } else if (amt > 0) { 142 result.append(buf, amt); 143 } 144 } 145 free(buf); 146 int status; 147 waitpid(pid, &status, 0); 148 if (WIFEXITED(status)) { 149 *err = WEXITSTATUS(status); 150 return result; 151 } else { 152 *err = -1; 153 return string(); 154 } 155 } 156 } 157 158 159 int 160 run_command(const Command& command) 161 { 162 print_command(command); 163 164 pid_t pid = fork(); 165 166 if (pid == -1) { 167 // fork error 168 return errno; 169 } else if (pid == 0) { 170 // child 171 const char* prog = command.GetProg(); 172 char* const* argv = command.GetArgv(); 173 char* const* env = command.GetEnv(); 174 exec_with_path_search(prog, argv, env); 175 print_error("Unable to run command: %s", prog); 176 exit(1); 177 } else { 178 // parent 179 int status; 180 waitpid(pid, &status, 0); 181 if (WIFEXITED(status)) { 182 return WEXITSTATUS(status); 183 } else { 184 return -1; 185 } 186 } 187 } 188 189 int 190 exec_with_path_search(const char* prog, char const* const* argv, char const* const* envp) 191 { 192 if (strchr(prog, '/') != NULL) { 193 return execve(prog, (char*const*)argv, (char*const*)envp); 194 } else { 195 char* pathEnv = strdup(getenv("PATH")); 196 if (pathEnv == NULL) { 197 return 1; 198 } 199 char* dir = pathEnv; 200 while (dir) { 201 char* next = strchr(dir, ':'); 202 if (next != NULL) { 203 *next = '\0'; 204 next++; 205 } 206 if (dir[0] == '/') { 207 struct stat st; 208 string executable = string(dir) + "/" + prog; 209 if (stat(executable.c_str(), &st) == 0) { 210 execve(executable.c_str(), (char*const*)argv, (char*const*)envp); 211 } 212 } 213 dir = next; 214 } 215 free(pathEnv); 216 return 1; 217 } 218 } 219 220
