PIPE(2) Linux Programmer's Manual PIPE(2) åå pipe, pipe2 - ãã¤ããçæãã æ¸å¼ #include <unistd.h> int pipe(int pipefd[2]); #define _GNU_SOURCE /* feature_test_macros(7) åç§ */ #include <fcntl.h> /* O_* å®æ°ã®å®ç¾©ã®åå¾ */ #include <unistd.h> int pipe2(int pipefd[2], int flags); 説æ pipe(2) ã¯ãã¤ããçæããã ãã¤ãã¯ããã‐ ã»ã¹ééä¿¡ã«ä½¿ç¨ã§ããåæ¹åã®ãã¼ã¿ãã£ãã«ã§ããã éå pipefd ã¯ããã¤ãã®ä¸¡ç«¯ãåç§ããäºã¤ã®ãã¡ã¤ã«ãã£ã¹ã¯ãªãã¿ã è¿ãã®ã«ä½¿ç¨ãããã pipefd[0] ããã¤ãã®èªã¿åºãå´ã pipefd[1] ããã¤ãã®æ¸ãè¾¼ã¿å´ã§ããã ãã¤ãã®æ¸ãè¾¼ã¿å´ã«æ¸ãè¾¼ã¾ãããã¼ã¿ã¯ã ãã¤ãã®èªã¿åºãå´ããèª‐ ã¿åºãããã¾ã§ã«ã¼ãã«ã§ãããã¡ãªã³ã°ãããã ãããªã詳細㯠pipe(7) ãåç§ã®ãã¨ã pipe2() 㯠flags ã 0 ã®å ´åã«ã¯ pipe() ã¨åãã§ããã flags ã«ä»¥ä¸ã®å¤ããããæ¯ã®è«çå (OR) ã§æå®ãããã¨ã§ã ç°ãªãåä½ãããããã¨ãã§ããã O_NONBLOCK æ°ããçæãããäºã¤ã®ãªã¼ãã³ãã¡ã¤ã«è¨è¿° (open file description) ã® O_NONBLOCK ãã¡ã¤ã«ã¹ãã¼ã¿ã¹ãã©ã°ãã»ããããã ãã®ãã©ã°ã使ããã¨ã§ã O_NONBLOCK ãã»ããããããã« fcntl(2) ã追å ã§å¼ã³åºãå¿è¦ããªããªãã O_CLOEXEC æ°ããçæãããäºã¤ã®ãã¡ã¤ã«ãã£ã¹ã¯ãªãã¿ã® close-on-exec (FD_CLOEXEC) ãã©ã°ãã»ããããã ãã®ãã©ã°ãå½¹ã«ç«ã¤çç±ã«ã¤ãã¦ã¯ã open(2) ã® O_CLOEXEC ãã©ã°ã®èª¬æãåç§ã®ãã¨ã è¿ãå¤ æåããå ´å㯠0 ãè¿ããããã¨ã©ã¼ã®å ´å㯠-1 ãè¿ããã errno ãé©åã«è¨å®ãããã ã¨ã©ã¼ EFAULT pipefd ãç¡å¹ãªå¤ã§ããã EINVAL (pipe2()) flags ã«ç¡å¹ãªå¤ãå¥ã£ã¦ããã EMFILE ãã®ããã»ã¹ã§ä½¿ããã¦ãããã¡ã¤ã«ãã£ã¹ã¯ãªãã¿ãå¤ãããã ENFILE ãªã¼ãã³ããã¦ãããã¡ã¤ã«ã®ç·æ°ãã·ã¹ãã ã®å¶éã«éãã¦ããã ãã¼ã¸ã§ã³ pipe2() ã¯ãã¼ã¸ã§ã³ 2.6.27 㧠Linux ã«è¿½å ãããã glibc ã«ãããµãã¼ãã¯ãã¼ã¸ã§ã³ 2.9 以éã§å©ç¨ã§ããã æºæ pipe(): POSIX.1-2001. pipe2() 㯠Linux åºæã§ããã ä¾ ä»¥ä¸ã®ããã°ã©ã ã§ã¯ãã¤ããçæãããã®å¾ fork(2) ã§åããã»ã¹ãçæããã åãã‐ ã»ã¹ã¯åããã¤ããåç§ãããã¡ã¤ã«ãã£ã¹ã¯ãªãã¿éåã®ã³ãã¼ã ç¶æ¿ããã fork(2) ã®å¾ãåããã»ã¹ã¯ãã¤ã (pipe(7) ãåç§) ã«å¿è¦ããªããªã£ããã£ã¹ã¯ãªãã¿ãã¯ã‐ ã¼ãºããã 親ããã»ã¹ã¯ããã°ã©ã ã®ã³ãã³ãã©ã¤ã³å¼ãæ°ã«å«ã¾ãã æå‐ åããã¤ãã¸æ¸ãè¾¼ã¿ã åããã»ã¹ã¯ãã®æååããã¤ããã 1 ãã¤ããã¤èª‐ ã¿è¾¼ãã§æ¨æºåºåã«ã¨ã³ã¼ããã #include <sys/wait.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> int main(int argc, char *argv[]) { int pipefd[2]; pid_t cpid; char buf; if (argc != 2) { fprintf(stderr, "Usage: %s <string>\n", argv[0]); exit(EXIT_FAILURE); } if (pipe(pipefd) == -1) { perror("pipe"); exit(EXIT_FAILURE); } cpid = fork(); if (cpid == -1) { perror("fork"); exit(EXIT_FAILURE); } if (cpid == 0) { /* åããã»ã¹ããã¤ãããèªã¿è¾¼ã */ close(pipefd[1]); /* 使ç¨ããªã write å´ã¯ã¯ãã¼ãºãã */ while (read(pipefd[0], &buf, 1) > 0) write(STDOUT_FILENO, &buf, 1); write(STDOUT_FILENO, "\n", 1); close(pipefd[0]); _exit(EXIT_SUCCESS); } else { /* 親ããã»ã¹ã¯ argv[1] ããã¤ãã¸æ¸ãè¾¼ã */ close(pipefd[0]); /* 使ç¨ããªã read å´ã¯ã¯ãã¼ãºãã */ write(pipefd[1], argv[1], strlen(argv[1])); close(pipefd[1]); /* èªã¿è¾¼ã¿å´ã EOF ã«åºä¼ã */ wait(NULL); /* åããã»ã¹ãå¾ã¤ */ exit(EXIT_SUCCESS); } } é¢é£é ç® fork(2), read(2), socketpair(2), write(2), popen(3), pipe(7) ãã®ææ¸ã«ã¤ã㦠ãã® man ãã¼ã¸ã¯ Linux man-pages ããã¸ã§ã¯ãã®ãªãªã¼ã¹ 3.51 ã®ä¸é¨ ã§ãããããã¸ã§ã¯ãã®èª¬æã¨ãã°å ±åã«é¢ããæå ±ã¯ http://www.kernel.org/doc/man-pages/ ã«æ¸ããã¦ããã Linux 2012-02-14 PIPE(2)