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Re: Pipes Again -- a simple test case
- From: Henri <houder at xs4all dot nl>
- To: cygwin at cygwin dot com
- Date: Mon, 11 Jan 2016 16:13:33 +0000 (UTC)
- Subject: Re: Pipes Again -- a simple test case
- Authentication-results: sourceware.org; auth=none
- References: <0aebd09993901f3ef3ff728d162952cd at xs4all dot nl> <568A32BE dot 4080101 at gmail dot com> <c7ebcc77c3ee94c4a81c48ebbdc81de9 at xs4all dot nl> <20160108151933 dot GI20447 at calimero dot vinschen dot de> <83235106e7ed2fcfde26293d156be51d at xs4all dot nl> <20160108163055 dot GK20447 at calimero dot vinschen dot de> <20160111115523 dot GD32610 at calimero dot vinschen dot de> <loom dot 20160111T162817-628 at post dot gmane dot org> <20160111154737 dot GA30417 at calimero dot vinschen dot de>
Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes:
> Can you please provide the socket testcase?
Trying to send you what you ask for (using gmane.org, I have to copy/paste)
----- t_stat3.c:
/*************************************************************************\
* Copyright (C) Michael Kerrisk, 2014. *
* *
* This program is free software. You may use, modify, and redistribute it *
* under the terms of the GNU Affero General Public License as published *
* by the Free Software Foundation, either version 3 or (at your option) *
* any later version. This program is distributed without any warranty. *
* See the file COPYING.agpl-v3 for details. *
\*************************************************************************/
/* Listing 15-1 */ // t_stat.c -- heavily modified
#define _BSD_SOURCE /* Get major() and minor() from <sys/types.h> */
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
//#include "file_perms.h"
//#include "tlpi_hdr.h"
#include <stdio.h> /* Standard I/O functions */
#include <stdlib.h> /* Prototypes of commonly used library functions,
plus EXIT_SUCCESS and EXIT_FAILURE constants */
#include <unistd.h> /* Prototypes for many system calls */
#include <string.h> /* Commonly used string-handling functions */
static void
displayStatInfo(const struct stat *sb)
{
printf("File type: ");
switch (sb->st_mode & S_IFMT) {
case S_IFREG: printf("regular file\n"); break;
case S_IFDIR: printf("directory\n"); break;
case S_IFCHR: printf("character device\n"); break;
case S_IFBLK: printf("block device\n"); break;
case S_IFLNK: printf("symbolic (soft) link\n"); break;
case S_IFIFO: printf("FIFO or pipe\n"); break;
case S_IFSOCK: printf("socket\n"); break;
default: printf("unknown file type?\n"); break;
}
printf("Device containing i-node: (%lx) major=%lu minor=%lu\n",
(long) sb->st_dev, (long) major(sb->st_dev), (long)
minor(sb->st_dev));
printf("I-node number: %llx - decimal: %llu\n", sb->st_ino,
sb->st_ino);
if (S_ISCHR(sb->st_mode) || S_ISBLK(sb->st_mode))
printf(" **** Device number (st_rdev): major=%ld; minor=%ld\n",
(long) major(sb->st_rdev), (long) minor(sb->st_rdev));
printf("File size: %lld bytes\n", (long long) sb->st_size);
}
void errExit(const char *format, ...);
#include <sys/un.h>
#include <sys/socket.h>
int
main()
{
char symlnk[64];
pid_t pid = getpid();
int sfd[2];
for (int f = 0; f < 2; f++) // step over the 1st and 2nd socket
{
if (!f) {
sfd[f] = socket(AF_UNIX, SOCK_STREAM, 0);
//sfd[f] = socket(AF_INET, SOCK_STREAM, 0);
if (sfd[f] == -1)
errExit("socket");
} else {
sfd[f] = socket(AF_UNIX, SOCK_STREAM, 0);
//sfd[f] = socket(AF_INET, SOCK_STREAM, 0);
if (sfd[f] == -1)
errExit("socket");
}
}
struct stat sb[2]; // one buffer for the 1st socket, one for the 2nd
int f;
char target[128];
ssize_t num;
printf("1st socket\n");
f = 0;
if (sprintf(symlnk, "/proc/%d/fd/%d", pid, sfd[f]) <= 0)
errExit("sprintf");
printf("... %s (symbolic link to the socket)\n", symlnk);
if ( (num = readlink( (const char *)symlnk, target, 128) ) == -1)
errExit("readlink");
if (num < 128) {
target[num] = '\0';
printf("... %s (target of symbolic link to the socket)\n", target);
printf("... using stat() on symbolic link: %s\n", symlnk);
//if (stat(target, sb + f) != 0) // not possible: target is NOT a
filename ...
if (stat(symlnk, sb + f) != 0)
errExit("stat");
displayStatInfo(sb + f);
printf("... using fstat()\n");
memset(sb + f, 0, sizeof(struct stat) ); // CLEAR
if (fstat(sfd[f], sb + f) != 0)
errExit("fstat");
displayStatInfo(sb + f);
}
#if 1
printf("\n2nd socket\n");
f = 1;
if (sprintf(symlnk, "/proc/%d/fd/%d", pid, sfd[f]) <= 0)
errExit("sprintf");
printf("... %s (symbolic link to the socket)\n", symlnk);
if ( (num = readlink( (const char *)symlnk, target, 128) ) == -1)
errExit("readlink");
if (num < 128) {
target[num] = '\0';
printf("... %s (target of symbolic link to the socket)\n", target);
printf("... using stat() on symbolic link: %s\n", symlnk);
//if (stat(target, sb + f) != 0) // not possible: target is NOT a
filename ...
if (stat(symlnk, sb + f) != 0)
errExit("stat");
displayStatInfo(sb + f);
printf("... using fstat()\n");
memset(sb + f, 0, sizeof(struct stat) ); // CLEAR
if (fstat(sfd[f], sb + f) != 0)
errExit("fstat");
displayStatInfo(sb + f);
}
#endif
close(sfd[0]);
close(sfd[1]);
exit(EXIT_SUCCESS);
}
#include <errno.h> /* Declares errno and defines error constants */
#include <stdarg.h>
#ifdef TRUE
#undef TRUE
#endif
#ifdef FALSE
#undef FALSE
#endif
typedef enum { FALSE, TRUE } Boolean;
static char *ename[] = {
/* 0 */ "",
/* 1 */ "EPERM", "ENOENT", "ESRCH", "EINTR", "EIO", "ENXIO",
/* 7 */ "E2BIG", "ENOEXEC", "EBADF", "ECHILD",
/* 11 */ "EAGAIN/EWOULDBLOCK", "ENOMEM", "EACCES", "EFAULT",
/* 15 */ "ENOTBLK", "EBUSY", "EEXIST", "EXDEV", "ENODEV",
/* 20 */ "ENOTDIR", "EISDIR", "EINVAL", "ENFILE", "EMFILE",
/* 25 */ "ENOTTY", "ETXTBSY", "EFBIG", "ENOSPC", "ESPIPE",
/* 30 */ "EROFS", "EMLINK", "EPIPE", "EDOM", "ERANGE", "ENOMSG",
/* 36 */ "EIDRM", "ECHRNG", "EL2NSYNC", "EL3HLT", "EL3RST",
/* 41 */ "ELNRNG", "EUNATCH", "ENOCSI", "EL2HLT", "EDEADLK",
/* 46 */ "ENOLCK", "", "", "", "EBADE", "EBADR", "EXFULL",
/* 53 */ "ENOANO", "EBADRQC", "EBADSLT", "EDEADLOCK", "EBFONT",
/* 58 */ "", "", "ENOSTR", "ENODATA", "ETIME", "ENOSR", "ENONET",
/* 65 */ "ENOPKG", "EREMOTE", "ENOLINK", "EADV", "ESRMNT",
/* 70 */ "ECOMM", "EPROTO", "", "", "EMULTIHOP", "ELBIN",
/* 76 */ "EDOTDOT", "EBADMSG", "", "EFTYPE", "ENOTUNIQ", "EBADFD",
/* 82 */ "EREMCHG", "ELIBACC", "ELIBBAD", "ELIBSCN", "ELIBMAX",
/* 87 */ "ELIBEXEC", "ENOSYS", "ENMFILE", "ENOTEMPTY",
/* 91 */ "ENAMETOOLONG", "ELOOP", "", "", "EOPNOTSUPP",
/* 96 */ "EPFNOSUPPORT", "", "", "", "", "", "", "", "ECONNRESET",
/* 105 */ "ENOBUFS", "EAFNOSUPPORT", "EPROTOTYPE", "ENOTSOCK",
/* 109 */ "ENOPROTOOPT", "ESHUTDOWN", "ECONNREFUSED", "EADDRINUSE",
/* 113 */ "ECONNABORTED", "ENETUNREACH", "ENETDOWN", "ETIMEDOUT",
/* 117 */ "EHOSTDOWN", "EHOSTUNREACH", "EINPROGRESS", "EALREADY",
/* 121 */ "EDESTADDRREQ", "EMSGSIZE", "EPROTONOSUPPORT",
/* 124 */ "ESOCKTNOSUPPORT", "EADDRNOTAVAIL", "ENETRESET",
/* 127 */ "EISCONN", "ENOTCONN", "ETOOMANYREFS", "EPROCLIM",
/* 131 */ "EUSERS", "EDQUOT", "ESTALE", "ENOTSUP", "ENOMEDIUM",
/* 136 */ "ENOSHARE", "ECASECLASH", "EILSEQ", "EOVERFLOW",
/* 140 */ "ECANCELED", "ENOTRECOVERABLE", "EOWNERDEAD", "ESTRPIPE"
};
#define MAX_ENAME 143
static void
terminate(Boolean useExit3)
{
char *s;
/* Dump core if EF_DUMPCORE environment variable is defined and
is a nonempty string; otherwise call exit(3) or _exit(2),
depending on the value of 'useExit3'. */
s = getenv("EF_DUMPCORE");
if (s != NULL && *s != '\0')
abort();
else if (useExit3)
exit(EXIT_FAILURE);
else
_exit(EXIT_FAILURE);
}
static void
outputError(Boolean useErr, int err, Boolean flushStdout,
const char *format, va_list ap)
{
#define BUF_SIZE 500
char buf[BUF_SIZE], userMsg[BUF_SIZE], errText[BUF_SIZE];
vsnprintf(userMsg, BUF_SIZE, format, ap);
if (useErr)
snprintf(errText, BUF_SIZE, " [%s %s]",
(err > 0 && err <= MAX_ENAME) ?
ename[err] : "?UNKNOWN?", strerror(err));
else
snprintf(errText, BUF_SIZE, ":");
snprintf(buf, BUF_SIZE, "ERROR%s %s\n", errText, userMsg);
if (flushStdout)
fflush(stdout); /* Flush any pending stdout */
fputs(buf, stderr);
fflush(stderr); /* In case stderr is not line-buffered */
}
void
errExit(const char *format, ...)
{
va_list argList;
va_start(argList, format);
outputError(TRUE, errno, TRUE, format, argList);
va_end(argList);
terminate(TRUE);
}
//=====
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