我得到了一个decrypt.jar和decrypt.jar文件，用于在传输之前准备文件。
当我启动terminal并input：
/usr/bin/java -jar /path/to/jar/decrypt.jar
我得到的输出：
No input file specified
哪个好！ jar子工作。 现在在我的代码中，当我用execl（）启动jar时，我得到这个输出：
Error: Could not find or load main class util.decrypt.jar Decryptor exited with 0
请注意，这里的问题是，java尝试启动实际上是jarpath的类（path是util / decrypt.jar，并将其作为类util.decrypt.jar执行）
我的代码：
bool decrypt_file(const std::string& file) { int result; int pipefd[2]; FILE *cmd_output; char buf[1024]; int status; result = pipe(pipefd); if (result < 0) { throw "pipe error!"; } pid_t pid = fork(); /* Create a child process */ const std::string decryptJar = "util/decrypt.jar"; int ex; if ( !fileExists(decryptJar) ) throw "File decryptor does not exist!"; switch (pid) { case -1: /* Error */ #ifdef _DEBUG std::cout<<"fork() failed!\n"; #endif return false; case 0: /* Child process */ dup2(pipefd[1], STDOUT_FILENO); /* Duplicate writing end to stdout */ close(pipefd[0]); close(pipefd[1]); //getJava() returns "/usr/bin/java" ex = execl(Config::getInstance().getJava().c_str(), "-jar", decryptJar.c_str(), file.c_str(), NULL); /* Execute the program */ #ifdef _DEBUG std::cout << "execl() failed! returned "<<ex<<", errno = "<<errno<<"\n"; /* execl doesn't return unless there's an error */ //todo if errno is 2, java was not found on the system, let the user know! #endif return false; default: /* Parent process */ int status; close(pipefd[1]); /* Close writing end of pipe */ cmd_output = fdopen(pipefd[0], "r"); #ifdef _DEBUG if (fgets(buf, sizeof buf, cmd_output)) { std::string str(buf); std::cout<<"OUTPUT: "<<str<<"\n"; } #endif while (!WIFEXITED(status)) { waitpid(pid, &status, 0); /* Wait for the process to complete */ } #ifdef _DEBUG std::cout << "Decryptor exited with " << WEXITSTATUS(status) << "\n"; #endif return true; } }
jar内的清单是正确的（它是由eclipse生成的）：
Manifest-Version: 1.0 Class-Path: . Main-Class: com.{...}.Decryptor
加：
试图将path更改为jar的绝对path并不能解决问题。
const std::string decryptJar = workingDir() + "/util/decrypt.jar";
解决了
愚蠢的错误从我这边来说，第一个论点应该按照惯例始终是可执行文件的路径。
所以
ex = execl(Config::getInstance().getJava().c_str(), "-jar", decryptJar.c_str(), file.c_str(), NULL); /* Execute the program */
应该
ex = execl(Config::getInstance().getJava().c_str(), decryptJar.c_str(), "-jar", decryptJar.c_str(), file.c_str(), NULL); /* Execute the program */
发生了什么事，是java把“ – jar”作为路径，因此我的命令实际上是
java pathToJar input
代替
java -jar pathToJar input
编辑：更正的代码片段：
bool decrypt_file(const std::string& javaPath, const std::string& file) { int result, status; int pipefd[2]; FILE *cmd_output; char buf[1024]; int ex; const std::string decryptJar = workingDir() + "/util/decrypt.jar"; result = pipe(pipefd); if (result < 0) { throw "pipe error!"; } pid_t pid = fork(); /* Create a child process */ if ( !fileExists(decryptJar) ) throw "File decryptor does not exist!"; switch (pid) { case -1: /* Error */ #ifdef _DEBUG std::cout<<"fork() failed!\n"; #endif return false; case 0: /* Child process */ dup2(pipefd[1], STDOUT_FILENO); /* Duplicate writing end to stdout */ close(pipefd[0]); close(pipefd[1]); ex = execl(javaPath.c_str(), decryptJar.c_str(), "-jar", decryptJar.c_str(), file.c_str(), NULL); /* Execute the program */ #ifdef _DEBUG std::cout << "execl() failed! returned "<<ex<<", errno = "<<errno<<"\n"; /* execl doesn't return unless there's an error */ #endif if ( errno == 2 ) { std::cout<<"JAVA NOT FOUND! Check if java is installed and/or if the path in the config file points to a correct java installation!\n\n"; } return false; default: /* Parent process */ close(pipefd[1]); /* Close writing end of pipe */ cmd_output = fdopen(pipefd[0], "r"); #ifdef _DEBUG if (fgets(buf, sizeof buf, cmd_output)) { std::string str(buf); if ( str != "OK" ) std::cout<<"---DECRYPT OUTPUT: "<<str<<"\n"; } #endif while (!WIFEXITED(status)) { waitpid(pid, &status, 0); /* Wait for the process to complete */ } #ifdef _DEBUG std::cout << "Decryptor exited with " << WEXITSTATUS(status) << "\n"; #endif return true; } }