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Full Discussion: cat file1 > file1
Operating Systems Solaris cat file1 > file1 Post 302406522 by asalman.qazi on Tuesday 23rd of March 2010 07:43:12 AM
Old 03-23-2010
cat file1 > file1

I have file1 with the contents
Code:
 
this is file1

when i do cat file1 , the output is

Code:
 
this is file1


when i run cat file1 > file1 , I receive the following message
Code:
 
cat: input file1 is output

now when i again do

cat file1 , all the contents are gone.

Can somebody explain what is happening?Smilie
 

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DIFF3(1)						      General Commands Manual							  DIFF3(1)

NAME
diff3 - 3-way differential file comparison SYNOPSIS
diff3 [ -ex3 ] file1 file2 file3 DESCRIPTION
Diff3 compares three versions of a file, and publishes disagreeing ranges of text flagged with these codes: ==== all three files differ ====1 file1 is different ====2 file2 is different ====3 file3 is different The type of change suffered in converting a given range of a given file to some other is indicated in one of these ways: f : n1 a Text is to be appended after line number n1 in file f, where f = 1, 2, or 3. f : n1 , n2 c Text is to be changed in the range line n1 to line n2. If n1 = n2, the range may be abbreviated to n1. The original contents of the range follows immediately after a c indication. When the contents of two files are identical, the contents of the lower-numbered file is suppressed. Under the -e option, diff3 publishes a script for the editor ed that will incorporate into file1 all changes between file2 and file3, i.e. the changes that normally would be flagged ==== and ====3. Option -x (-3) produces a script to incorporate only changes flagged ==== (====3). The following command will apply the resulting script to `file1'. (cat script; echo '1,$p') | ed - file1 FILES
/tmp/d3????? /usr/lib/diff3 SEE ALSO
diff(1) BUGS
Text lines that consist of a single `.' will defeat -e. Files longer than 64K bytes won't work. DIFF3(1)
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