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Top Forums Shell Programming and Scripting File descriptors -- cygwyn bash (windows) Post 302725903 by joed270 on Friday 2nd of November 2012 08:07:36 PM
Old 11-02-2012
File descriptors -- cygwyn bash (windows)

Cygwin bash script was invoked in bash shell as follows:
Code:
/cygdrive/c/cygwin/bin/bash  test.sh

This is content of my script
Code:
 #!/bin/bash
 #
 exec 3</cygdrive/c/cygwin/home/work/part1.txt
 read -u 3 x
 echo $x
 exec 3<&-

Commands work correctly when issued one at a time within bash shell.
But when I attempt to run the shell script I get error messages like this:
Code:
: No such file or directoryc/cygwin/home/work/part1.txt
  test.sh: line 4: read: 3: invalid file descriptor: Bad file  descriptor
: not foundne 6: exec:

Any ideas on why the script fails?
 

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RBASH(1)						      General Commands Manual							  RBASH(1)

NAME
rbash - restricted bash, see bash(1) RESTRICTED SHELL
If bash is started with the name rbash, or the -r option is supplied at invocation, the shell becomes restricted. A restricted shell is used to set up an environment more controlled than the standard shell. It behaves identically to bash with the exception that the follow- ing are disallowed or not performed: o changing directories with cd o setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV o specifying command names containing / o specifying a file name containing a / as an argument to the . builtin command o specifying a filename containing a slash as an argument to the -p option to the hash builtin command o importing function definitions from the shell environment at startup o parsing the value of SHELLOPTS from the shell environment at startup o redirecting output using the >, >|, <>, >&, &>, and >> redirection operators o using the exec builtin command to replace the shell with another command o adding or deleting builtin commands with the -f and -d options to the enable builtin command o using the enable builtin command to enable disabled shell builtins o specifying the -p option to the command builtin command o turning off restricted mode with set +r or set +o restricted. These restrictions are enforced after any startup files are read. When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script. SEE ALSO
bash(1) GNU Bash-4.0 2004 Apr 20 RBASH(1)
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