Cannot redirect to STDIN in a shell script

metaltree · #1 (**permalink**) 02-10-2009

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?

zaxxon · #2 (**permalink**) 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.

metaltree · #3 (**permalink**) 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.

just4fundoit · #4 (**permalink**) 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

metaltree · #5 (**permalink**) 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")'

vgersh99 · #6 (**permalink**) 02-11-2009

Code:

-bash-3.1$ cat myScript 
#!/bin/bash
cat <(printf "aaa\nbbb\n") <(printf "111\n222\n")

metaltree · #7 (**permalink**) 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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