comparison: src/process.cpp
src/process.cpp
- changeset 2
- 7384ebae6b7c
- child 4
- 82680ce258d6
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| 1:9bf126bc825c | 2:7384ebae6b7c |
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| 1 /* Copyright 2025 Mike Becker. All rights reserved. | |
| 2 * | |
| 3 * Redistribution and use in source and binary forms, with or without | |
| 4 * modification, are permitted provided that the following conditions are met: | |
| 5 * | |
| 6 * 1. Redistributions of source code must retain the above copyright | |
| 7 * notice, this list of conditions and the following disclaimer. | |
| 8 * | |
| 9 * 2. Redistributions in binary form must reproduce the above copyright | |
| 10 * notice, this list of conditions and the following disclaimer in the | |
| 11 * documentation and/or other materials provided with the distribution. | |
| 12 * | |
| 13 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 16 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE | |
| 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
| 19 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |
| 20 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
| 21 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 22 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 23 */ | |
| 24 | |
| 25 #include "process.h" | |
| 26 | |
| 27 #include <cstdio> | |
| 28 #include <cstdlib> | |
| 29 #include <fcntl.h> | |
| 30 #include <unistd.h> | |
| 31 #include <sys/wait.h> | |
| 32 | |
| 33 using namespace fm; | |
| 34 | |
| 35 process::process(std::string path): m_path(std::move(path)) { | |
| 36 } | |
| 37 | |
| 38 bool process::exec(std::vector<std::string> args) { | |
| 39 // fd-pair for the pipe | |
| 40 int pipefd[2]; | |
| 41 | |
| 42 if (pipe(pipefd)) { | |
| 43 perror("pipe"); | |
| 44 return false; | |
| 45 } | |
| 46 | |
| 47 pid_t pid = fork(); | |
| 48 if (pid == 0) { | |
| 49 // connect the pipe and close the end we don't use | |
| 50 if (dup2(pipefd[1], STDOUT_FILENO) == -1) { | |
| 51 perror("pipe"); | |
| 52 exit(EXIT_FAILURE); | |
| 53 } | |
| 54 close(pipefd[0]); | |
| 55 | |
| 56 // create the execv argument list | |
| 57 char *argv[args.size() + 2] = {}; | |
| 58 auto slash = m_path.find_last_of('/'); | |
| 59 if (slash == std::string::npos) { | |
| 60 argv[0] = m_path.data(); | |
| 61 } else { | |
| 62 argv[0] = m_path.data() + slash + 1; | |
| 63 } | |
| 64 unsigned i = 0; | |
| 65 for (auto&& arg : args) { | |
| 66 argv[++i] = arg.data(); | |
| 67 } | |
| 68 argv[args.size() + 1] = nullptr; | |
| 69 | |
| 70 // execute the child program | |
| 71 if (execv(m_path.c_str(), argv)) { | |
| 72 perror("execl"); | |
| 73 exit(EXIT_FAILURE); | |
| 74 } | |
| 75 return true; // unreachable, but the compiler doesn't know that | |
| 76 } else if (pid > 0) { | |
| 77 // close the end of the pipe we don't use | |
| 78 close(pipefd[1]); | |
| 79 | |
| 80 // read all the output | |
| 81 char buf[64]; | |
| 82 ssize_t r; | |
| 83 while ((r = read(pipefd[0], buf, sizeof(buf))) > 0) { | |
| 84 m_output.append(buf, r); | |
| 85 } | |
| 86 if (r < 0) { | |
| 87 perror("read"); | |
| 88 } | |
| 89 close(pipefd[0]); | |
| 90 | |
| 91 // wait for the process to completely finish | |
| 92 int status = -1; | |
| 93 waitpid(pid, &status, 0); | |
| 94 | |
| 95 return status == 0; | |
| 96 } else { | |
| 97 perror("fork"); | |
| 98 return false; | |
| 99 } | |
| 100 } | |
| 101 | |
| 102 const std::string &process::output() const { | |
| 103 return m_output; | |
| 104 } |
