Cat Write Error Bad File Number
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Bad File Descriptor Socket
Join them; it only takes a minute: Sign up Bad file descriptor up vote 11 down vote favorite 1 I'm learning about file descriptors and I wrote this code: #include
What Is Bad File Descriptor
fdrd, fdwr, fdwt; char c; main (int argc, char *argv[]) { if((fdwt = open("output", O_CREAT, 0777)) == -1) { perror("Error opening the file:"); exit(1); } char c = 'x'; if(write(fdwt, &c, 1) == -1) { perror("Error writing the file:"); } close(fdwt); exit(0); } , but I'm getting: Error writing the file:: Bad file descriptor I don't know what could be wrong, since this is a very simple example. c file unix file-descriptor share|improve this question edited Mar 16 bad file descriptor error in c '14 at 15:05 Sheena 5,24563566 asked Jun 5 '11 at 19:57 Lucy 76126 What is the val of fdwt on return from open( )? It should be a small integer, like less than 5. In fact, because no other fds are open in this code, it should be 3 (i.e., STDERR + 1). –Pete Wilson Jun 5 '11 at 20:11 1 Incidentally, your code has several problematic bits. Those variables don't need to be global (few ever do), you should declare them in main. You also declare c twice, you don't need the char in char c the second time. At the same time, the second declaration of c in the middle of the function is only valid in C99, but you declare main without a return type -- which is invalid in C99, which eliminates the "implicit int" rule that was present in C89 and earlier versions of C. Most compilers should issue warnings for that, some will throw an error and refuse to compile. –Nicholas Knight Jun 5 '11 at 20:27 You should accept an answer! –gsamaras Feb 18 '15 at 17:24 add a comment| 3 Answers 3 active oldest votes up vote 14 down vote Try this: open("output", O_CREAT|O_WRONLY, 0777) share|improve this answer answered Jun 5 '11 at 20:02 patapizza 2,018712 Wow! So fast! :) That worked! Now I have to f
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Bad File Descriptor Bash
25 Oct 2006 12:55:41 +0200 Cc: zsh-users Mailinglist
HAT RUBY SAP SEARCH SILVERLIGHT SYMBIAN VIDEO VIRTUALIZATION WEB 2.0 WEBLOGIC WEBSPHERE WIRELESS XML Home Subscribe Advertise Authors Topics Videos Events Webcasts http://linux.sys-con.com/node/1053821 Internet of Things | Cloud | Big Data | DevOps | Containers | Microservices | WebRTC | Java | Linux | Open Stack | Mobile | Security | https://www.gnu.org/software/autoconf/manual/autoconf-2.67/html_node/File-Descriptors.html SDDC Linux Containers Authors: Ian Khan, Liz McMillan, Pat Romanski, Elizabeth White, David Paquette Related Topics: Linux Containers Linux Containers: Article Bad File Descriptor Error in Linux bad file Stellar Phoenix Linux Data Recovery is a comprehensive data recovery tool By Allen Sood Article Rating: Select ratingGive it 1/5Give it 2/5Give it 3/5Give it 4/5Give it 5/5 July 30, 2009 04:30 AM EDT Reads: 69,370 Related Print Email Feedback Add This Blog This In a Linux system, files, blocks, directories, sockets and other items are referred by corresponding file descriptors. bad file descriptor If your system is reporting errors that the file descriptor is bad, one of possible causes is that file system is corrupt and thus, you require restoring from backup. But if backup is not valid enough to restore complete information, you need to use advanced Linux Data Recovery applications. As an instance, you might encounter the below error message with your Linux based system: “Bad file descriptor” You might receive this error while trying to access a file or while trying to boot the system. Cause Possible reasons for the ‘Bad file descriptor’ error to occur are: Linux systems use a special file, called /dev/null (also called the null device). This file removes all the data that is written to it after reporting that the write process has successfully succeeded. You might receive the above error message if /dev/null has been deleted or overwritten. You can infer this cause when file system is reported as read-only at the time of booting through error messages, such as“/dev/null: Read-only filesystem” and “dup2: bad file descriptor” If you get this error message while tryin
you meant to capture the standard-error output of the inner command: $ ash -x -c '(eval "echo foo >&2") 2>stderr' $ cat stderr + eval echo foo >&2 + echo foo foo $ bash -x -c '(eval "echo foo >&2") 2>stderr' $ cat stderr + eval 'echo foo >&2' ++ echo foo foo $ zsh -x -c '(eval "echo foo >&2") 2>stderr' # Traces on startup files deleted here. $ cat stderr +zsh:1> eval echo foo >&2 +zsh:1> echo foo foo One workaround is to grep out uninteresting lines, hoping not to remove good ones. If you intend to redirect both standard error and standard output, redirect standard output first. This works better with HP-UX, since its shell mishandles tracing if standard error is redirected first: $ sh -x -c ': 2>err >out' + : + 2> err $ cat err 1> out Don't try to redirect the standard error of a command substitution. It must be done inside the command substitution. When running ‘: `cd /zorglub` 2>/dev/null’ expect the error message to escape, while ‘: `cd /zorglub 2>/dev/null`’ works properly. On the other hand, some shells, such as Solaris or FreeBSD /bin/sh, warn about missing programs before performing redirections. Therefore, to silently check whether a program exists, it is necessary to perform redirections on a subshell: $ /bin/sh -c 'nosuch 2>/dev/null' nosuch: not found $ /bin/sh -c '(nosuch) 2>/dev/null' $ bash -c 'nosuch 2>/dev/null' FreeBSD 6.2 sh may mix the trace output lines from the statements in a shell pipeline. It is worth noting that Zsh (but not Ash nor Bash) makes it possible in assignments though: ‘foo=`cd /zorglub` 2>/dev/null’. Some shells, like ash, don't recognize bi-directional redirection (‘<>’). And even on shells that recognize it, it is not portable to use on fifos: Posix does not require read-write support for named pipes, and Cygwin does not support it: $ mkfifo fifo $ exec 5<>fifo $ echo hi >&5 bash: echo: write error: Communication error on send When catering to old systems, don't redirect the same file descriptor several times, as you are doomed to failure under Ultrix. ULTRIX V4.4 (Rev. 69) System #31: Thu Aug 10 19:42:23 GMT 1995 UWS V4.4 (Rev. 11) $ eval 'echo matter >fullness' >void illegal io $ eval '(echo matter >fullness)' >void illegal io $ (eval '(echo matter >fullness)') >void Ambiguous output redirect. In each case the expected result is of course fullness containing ‘matter’ and void being empty. However, this bug is probably not of practical concern to modern platforms. Solaris 10 sh will tr