GETPROTOENT_R(3) Linux Programmer's Manual GETPROTOENT_R(3) åå getprotoent_r, getprotobyname_r, getprotobynumber_r - ãããã³ã« ã¨ã³ããªãåå¾ãã (ãªã¨ã³ãã©ã³ãç) æ¸å¼ #include <netdb.h> int getprotoent_r(struct protoent *result_buf, char *buf, size_t buflen, struct protoent **result); int getprotobyname_r(const char *name, struct protoent *result_buf, char *buf, size_t buflen, struct protoent **result); int getprotobynumber_r(int proto, struct protoent *result_buf, char *buf, size_t buflen, struct protoent **result); glibc åãã®æ©è½æ¤æ»ãã¯ãã®è¦ä»¶ (feature_test_macros(7) åç§): getprotoent_r(), getprotobyname_r(), getprotobynumber_r(): _BSD_SOURCE || _SVID_SOURCE 説æ é¢æ° getprotoent_r(), getprotobyname_r(), getprotobynumber_r() ã¯ããããã getprotoent(3), getprotobyname(3), getprotobynumber(3) ã®ãªã¨ã³ãã©ã³ãçã§ããã protoent æ§é ä½ã®è¿ãæ¹ã¨ãé¢æ°å¼ã³åºãæã®å¼ãæ°ã¨è¿ãå¤ãç°ãªãã ãã®ããã¥ã¢ã«ãã¼ã¸ã§ã¯ããªã¨ã³ãã©ã³ãã§ãªãé¢æ°ã¨ã®éãã ãã 説æããã ãããã®é¢æ°ã¯ãé¢æ°ã®çµæã¨ãã¦éçã«å²ãå½ã¦ããã protoent æ§é ä½ ã¸ã®ãã¤ã³ã¿ãè¿ãã®ã§ã¯ãªãã protoent æ§é ä½ã result_buf ã æãå ´æã«ã³ãã¼ããã éå buf ã¯ãè¿ããã protoent æ§é ä½ãæãæååãã£ã¼ã«ãã æ ¼ç´ããã®ã«ä½¿ç¨ããã (ãªã¨ã³ãã©ã³ãã§ãªãé¢æ°ã®å ´åã¯ã ãããã®æååã¯éçãªé åã«æ ¼ç´ããã)ã ãã®éåã®å¤§ãã㯠buflen ã§æå®ãããã buf ãå°ããããå ´åãé¢æ°å¼ã³åºãã¯ã¨ã©ã¼ ERANGE ã§å¤±æãã å¼ã³åºãå´ã§ã¯ãã£ã¨å¤§ããªãããã¡ã§å度å¼ã³åºãå¿è¦ããã (ã»ã¨ãã©ã® ã¢ããªã±ã¼ã·ã§ã³ã§ã¯ãé·ã 1024 ãã¤ãã®ãããã¡ã§ååãªã¯ãã§ãã)ã é¢æ°å¼ã³åºãã§ãããã³ã«ã¬ã³ã¼ãã®åå¾ã«æåããã¨ã *result 㯠result_buf ãæãããã«è¨å®ãããã ãã以å¤ã®å ´å㯠*result ã« NULL ãè¨å®ãããã è¿ãå¤ æåããã¨ããããã®é¢æ°ã¯ 0 ãè¿ããã¨ã©ã¼ã®å ´åããã¨ã©ã¼ãã®ç¯ã® ãªã¹ãã«ããæ‐ £ã®ã¨ã©ã¼çªå·ã®ãããããè¿ãã ã¨ã©ã¼ã®å ´åãã¬ã³ã¼ããè¦ã¤ãããªãã£ãå ´å (getprotobyname_r(), getprotobyaddr_r()) ããã以ä¸ã¬ã³ã¼ãããªãå ´å (getprotoent_r())ãresult ã«ã¯ NULL ãè¨å®ãããã ã¨ã©ã¼ ENOENT (getprotoent_r()) ãã¼ã¿ãã¼ã¹ã«ãã以ä¸ã¬ã³ã¼ãããªãã ERANGE buf ãå°ããããããã£ã¨å¤§ããªãããã¡ã«ã㦠(ã¾ã㯠buflen ãå¢ããã¦) å度å¼ã³åºããã¨ã æºæ ãããã®é¢æ°ã¯ GNU ã«ããæ¡å¼µã§ããã ä»ã®ã·ã¹ãã ã«ãåæ§ã®ååã®é¢æ°ãå‐ å¨ããå ´åããããã é常ã¯é¢æ°ã®å¼ãæ°ãç°ãªãã ä¾ ä»¥ä¸ã®ããã°ã©ã ã¯ã getprotobyname_r() ã使ã£ã¦ãæåã®ã³ãã³ã ã©ã¤ã³å¼ãæ°ã§æå®ãããååã®ãããã³ã«ã®ã¬ã³ã¼ããåå¾ããã äºçªç®ã®ã³ãã³ãã©ã¤ã³å¼ãæ° (æ´æ°å¤) ãæå®ãããå ´åã¯ã ãã®å¤ã buflen ã®åæå¤ã¨ãã¦ä½¿ç¨ãããã getprotobyname_r() ãã¨ã©ã¼ ERANGE ã§å¤±æããã¨ããã‐ ã°ã©ã 㯠ãã大ããªãããã¡ãµã¤ãºã§å度 getprotobyname_r ãå¼ã³åºãã ä¸è¨ã®ã·ã§ã«ã®ã»ãã·ã§ã³ã¯ãå®è¡ä¾ã示ãã¦ããã $ ./a.out tcp 1 ERANGE! Retrying with larger buffer getprotobyname_r() returned: 0 (success) (buflen=78) p_name=tcp; p_proto=6; aliases=TCP $ ./a.out xxx 1 ERANGE! Retrying with larger buffer getprotobyname_r() returned: 0 (success) (buflen=100) Call failed/record not found ããã°ã©ã ã®ã½ã¼ã¹ #define _GNU_SOURCE #include <ctype.h> #include <netdb.h> #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <string.h> #define MAX_BUF 10000 int main(int argc, char *argv[]) { int buflen, erange_cnt, s; struct protoent result_buf; struct protoent *result; char buf[MAX_BUF]; char **p; if (argc < 2) { printf("Usage: %s proto-name [buflen]\n", argv[0]); exit(EXIT_FAILURE); } buflen = 1024; if (argc > 2) buflen = atoi(argv[2]); if (buflen > MAX_BUF) { printf("Exceeded buffer limit (%d)\n", MAX_BUF); exit(EXIT_FAILURE); } erange_cnt = 0; do { s = getprotobyname_r(argv[1], &result_buf, buf, buflen, &result); if (s == ERANGE) { if (erange_cnt == 0) printf("ERANGE! Retrying with larger buffer\n"); erange_cnt++; /* Increment a byte at a time so we can see exactly what size buffer was required */ buflen++; if (buflen > MAX_BUF) { printf("Exceeded buffer limit (%d)\n", MAX_BUF); exit(EXIT_FAILURE); } } } while (s == ERANGE); printf("getprotobyname_r() returned: %s (buflen=%d)\n", (s == 0) ? "0 (success)" : (s == ENOENT) ? "ENOENT" : strerror(s), buflen); if (s != 0 || result == NULL) { printf("Call failed/record not found\n"); exit(EXIT_FAILURE); } printf("p_name=%s; p_proto=%d; aliases=", result_buf.p_name, result_buf.p_proto); for (p = result_buf.p_aliases; *p != NULL; p++) printf("%s ", *p); printf("\n"); exit(EXIT_SUCCESS); } é¢é£é ç® getprotoent(3), protocols(5) 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 GNU 2010-09-10 GETPROTOENT_R(3)