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Shell Programming and Scripting

Cannot redirect to STDIN in a shell script

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# 1  
Old 02-10-2009
Cannot redirect to STDIN in a shell script
I am unable to use STDIn redirection with < (commands)
When I do the following, both approaches work and give the same results:

1.
Code:
$ printf "aaa\nbbb\n" > file1
$ printf "111\n222\n" > file2
$ cat file1 file2
aaa
bbb
111
222

2.
Code:
$ cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")
aaa
bbb
111
222

However, the second approach won't work when I put in in a script.

I am using Cygwin1.5.25-15

Any clue?
# 2  
Old 02-11-2009
From the manual page of cat:
Code:
...
cat - concatenate files and print on the standard output
...

You should feed the cat with files to hear it purr.
# 3  
Old 02-11-2009
What I don't understand is that the command with < () redirection works perfectly as a single line, but not when included in a script.
# 4  
Old 02-11-2009
Thats the issue with the emulators. Dont get confused, emulators are not real shells, they are made to mimic some of the qualities of shells ! If you try that on a Bash/sh/ksh/csh it will works fine.
-Peace
# 5  
Old 02-11-2009
Thanks, but apparently this goes beyond the Cygwin element.

I tried that on a Linux bash:

1. Works fine as a line:
Code:
-bash-3.1$ cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")
aaa
bbb
111
222

2. Won't work as a script:
Code:
 
-rw-r--r-- 1 cleseb01 cleseb01 51 Feb 11 16:27 script
-bash-3.1$ cat script 
cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")
 
-bash-3.1$ sh script 
script: line 1: syntax error near unexpected token `('
script: line 1: `cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")'

# 6  
Old 02-11-2009
Code:
-bash-3.1$ cat myScript 
#!/bin/bash
cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")

# 7  
Old 02-11-2009
Code:
$ cat script
#!/bin/bash
cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")

Code:
 
$ sh script
script: line 2: syntax error near unexpected token `('
script: line 2: `cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")'
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