UNIX for Dummies Questions & Answers

Hi,

I ahve come across one of the trickier scenario and wanted to check anyone came across this:
i have a file called file1:

Code:

pandi.desktop% cat file1
aa
cc
ds
wwe
bb
pandi.desktop%

I want to read input from keyboard and append into the original file. besides that i want to sort the whole content and write it to a new file.
i want to accomplish this in a oneliner with out using any '&&' or ';'

Code:

sort - file1>>file2

works but the new content added is not being written in the original file. But the new file comes as expected.

Code:

pandi.desktop% sort - file1>>file2
bbs
cc
ff
pandi.desktop% cat file1
aa
cc
ds
wwe
bb
pandi.desktop% cat file2
aa
bb
bbs
cc
cc
ds
ff
wwe

Thanks in advance

You need to do this in two steps: 1) append stdin to file1 2) sort file1 to file2:

Code:

$ cat >>file1; sort file1 >file2

Or try this:

Code:

$ cat file1 - | tee  file1 | sort >file2

But the second is highly dependent on the timing when the shell opens/closes file1 during creation and execution of the pipe, so it will work more by sheer accident.