POSIX Message Queue を使ってプロセス間通信をする

#include <mqueue.h> #include <sys/stat.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <errno.h> #define QNAME "/testq" int main(){ int cnt = 0; int ret; char str[100]; char *buff; mqd_t q; struct mq_attr attr; attr.mq_flags = 0; attr.mq_maxmsg = 10; attr.mq_msgsize = 1024; attr.mq_curmsgs = 0; mode_t omask; omask = umask(0); q = mq_open(QNAME, (O_WRONLY | O_CREAT), 0777, &attr); umask(omask); if ( q == -1 ){ printf("[ERROR]%d: %s\n", errno, strerror(errno)); return 1; } while(1){ sprintf(str ,"%d", cnt++); buff = (char *)calloc(strlen(str) + 1, sizeof(char)); strcpy( buff, str ); printf("%s\n", buff); ret = mq_send( q, buff , strlen(buff) , 0); if ( ret == -1 ) { printf("[ERROR]%d: %s\n", errno, strerror(errno)); return 1; } free(buff); sleep(1); } }

#include <mqueue.h> #include <sys/stat.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <errno.h> #define QNAME "/testq" int main(){ mqd_t q; struct mq_attr attr; char *buff; ssize_t n; int i; q = mq_open(QNAME, O_RDONLY); if ( q == -1 ){ printf("[ERROR]%d: %s\n", errno, strerror(errno)); return 1; } while(1){ mq_getattr( q ,&attr ); buff = (char *)malloc(attr.mq_msgsize); n = mq_receive( q, buff, attr.mq_msgsize, NULL); if ( n == -1 ) { printf("[ERROR]%d: %s\n", errno, strerror(errno)); return 1; } for (i = 0; i < n; i++) putchar(buff[i]); putchar('\n'); fflush(stdout); free(buff); } }