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 pipe(fds); 109 110 pid_t pid = fork(); 111 112 if (pid == -1) { 113 // fork error 114 *err = errno; 115 return string(); 116 } else if (pid == 0) { 117 // child 118 while ((dup2(fds[1], STDOUT_FILENO) == -1) && (errno == EINTR)) {} 119 close(fds[1]); 120 close(fds[0]); 121 const char* prog = command.GetProg(); 122 char* const* argv = command.GetArgv(); 123 char* const* env = command.GetEnv(); 124 exec_with_path_search(prog, argv, env); 125 if (!quiet) { 126 print_error("Unable to run command: %s", prog); 127 } 128 exit(1); 129 } else { 130 // parent 131 close(fds[1]); 132 string result; 133 const int size = 16*1024; 134 char* buf = (char*)malloc(size); 135 while (true) { 136 ssize_t amt = read(fds[0], buf, size); 137 if (amt <= 0) { 138 break; 139 } else if (amt > 0) { 140 result.append(buf, amt); 141 } 142 } 143 free(buf); 144 int status; 145 waitpid(pid, &status, 0); 146 if (WIFEXITED(status)) { 147 *err = WEXITSTATUS(status); 148 return result; 149 } else { 150 *err = -1; 151 return string(); 152 } 153 } 154 } 155 156 157 int 158 run_command(const Command& command) 159 { 160 print_command(command); 161 162 pid_t pid = fork(); 163 164 if (pid == -1) { 165 // fork error 166 return errno; 167 } else if (pid == 0) { 168 // child 169 const char* prog = command.GetProg(); 170 char* const* argv = command.GetArgv(); 171 char* const* env = command.GetEnv(); 172 exec_with_path_search(prog, argv, env); 173 print_error("Unable to run command: %s", prog); 174 exit(1); 175 } else { 176 // parent 177 int status; 178 waitpid(pid, &status, 0); 179 if (WIFEXITED(status)) { 180 return WEXITSTATUS(status); 181 } else { 182 return -1; 183 } 184 } 185 } 186 187 int 188 exec_with_path_search(const char* prog, char const* const* argv, char const* const* envp) 189 { 190 if (prog[0] == '/') { 191 return execve(prog, (char*const*)argv, (char*const*)envp); 192 } else { 193 char* pathEnv = strdup(getenv("PATH")); 194 if (pathEnv == NULL) { 195 return 1; 196 } 197 char* dir = pathEnv; 198 while (dir) { 199 char* next = strchr(dir, ':'); 200 if (next != NULL) { 201 *next = '\0'; 202 next++; 203 } 204 if (dir[0] == '/') { 205 struct stat st; 206 string executable = string(dir) + "/" + prog; 207 if (stat(executable.c_str(), &st) == 0) { 208 execve(executable.c_str(), (char*const*)argv, (char*const*)envp); 209 } 210 } 211 dir = next; 212 } 213 free(pathEnv); 214 return 1; 215 } 216 } 217 218
