[BusyBox 0006254]: tac allows stdin to be specified more than once (mismatch with coreutils)

[bugs at busybox.net]

The following issue has been SUBMITTED. 
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http://busybox.net/bugs/view.php?id=6254 
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Reported By:                pgbovine
Assigned To:                BusyBox
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Project:                    BusyBox
Issue ID:                   6254
Category:                   Standards Compliance
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
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Date Submitted:             11-11-2008 13:30 PST
Last Modified:              11-11-2008 13:30 PST
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Summary:                    tac allows stdin to be specified more than once
(mismatch with coreutils)
Description: 
the '-' argument to tac tells it to read from stdin.  coreutils does not
allow '-' to be specified more than once in a given invocation.  e.g.,:

Coreutils behavior:

$ echo 'hello' | tac -
hello
$ echo $?
0

(regular behavior, exits with successful 0 exitcode)

$ echo 'hello' | tac - -
tac: cannot create temporary file `/tmp/tacBdLMmJ': Invalid argument
hello
$ echo $?
1

(error due to second '-', exits with 1)

In contrast, busybox doesn't seem to complain about the extra '-':

Busybox behavior:

$ echo 'hello' | ./busybox tac -
hello
$ echo $?
0

$ echo 'hello' | ./busybox tac - -
hello
$ echo $?
0

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Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
11-11-08 13:30  pgbovine       New Issue                                    
11-11-08 13:30  pgbovine       Status                   new => assigned     
11-11-08 13:30  pgbovine       Assigned To               => BusyBox         
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