How to redirect the output of two commands?

How to redirect the output of two commands?

How can i make the output of both commands be directed into the same file. Either use ‘append’ with >> or use braces to encompass the I/O redirections, or (occasionally) use exec:

How to save output of multiple commands to the same file?

In order to prevent having to type the path multiple times you could just save it in a variable: But this requires multiple redirections as well. If you wanted to write a long script or subset of commands and wanted to perform a single redirection for them you could use command grouping:

How to send text back to same file?

Basically I want to take as input text from a file, remove a line from that file, and send the output back to the same file. Something along these lines if that makes it any clearer. grep -v ‘seg[…

How to combine all lines in a text file?

It’s another solution and simple easy. 500212262578-4-423200GRIFFITH LABORATORIES LTDGRIFFITH LABORATORIESSOUTH DUBLIN COUNTY COUNCILOFFICEOFFICE (INDUSTRIAL)List Rateable2 Pineview Industrial EstateFirhouse RoadKnocklyon31 Dec 200701 Jan 2008″

How to concatenate multiple lines of output to one line?

You could use awk to change the output record separator like: Piping output to xargs will concatenate each line of output to a single line with spaces: Or any command, eg. ls | xargs.

How to echo results to one line in Bash?

An alternate way to echo results to one line would be to simply assign the results to variables. Example: This is particularly useful when you have more complex functions, maybe a complex ‘awk’ statement to pull out a particular cell in a row, then pair it with another set.

How to read same file simultaneously with two different programs?

Flow of program: C based CGI is used CGI1: -Gets called when user hits upload button (submit) ie form action = CGI1 -Does the file upload (copy to a directory etc) JS, Ajax fucntion: -A JS function is called when user hits upload button -The JS function opens an Ajax request for CGI2… 5. UNIX for Dummies Questions & Answers

Can you run two scripts at the same time?

Can both scripts run at the same time and read from file1.txt simultaneously? Unsynchronized simultaneous reads are not a problem. Regarding the example you gave, though, it could be accomplished in a single pass by a single process (sed or awk, to name a couple tools). Thanks for your response, Alister. What do you mean by unsynchronized?

What does unsynchronized read at the same time mean?

Unsynchronized means the readers of the file read whatever they want to read whenever they need to read it. You can have large number of processes reading a file at exactly the same time. If you have too many you can reach I/O saturation on huge files.

How to concatenate files from a batch file?

At its most basic, concatenating files from a batch file is done with ‘copy’. Place all files need to copied in a separate folder, for ease place them in c drive. Open Command Prompt – windows>type cmd>select command prompt. You can see the default directory pointing – Ex : C: [Folder_Name]>.

How to concatenate text files in win 7?

In Win 7, navigate to the directory where your text files are. On the command prompt use: Where combined.txt is the name of the newly created text file. I am reiterating some of the other points already made, but including a 3rd example that helps when you have files across folders that you want to concatenate.

How to redirect stdout and stderr in command line?

In order to redirect STDERR you have to specify ‘2>’ for the redirection symbol. This selects the second output stream which is STDERR. The command dir file.xxx (where file.xxx does not exist) will display the following output:

How to redirect output to a descriptor?

Thus only stdout is pointing at the file, because stderr is pointing to the “old” stdout. Another common use for redirecting output is redirecting only stderr. To redirect a file descriptor, we use N>, where N is a file descriptor.

Which is output to stdout and which to stderr?

Let’s say you have stderr output mingled with stdout output – perhaps you’re running the same command over many files, and the command may output to stdout or stderr each time. For convenience, the command outputs “stdout” to stdout, and “stderr” to stderr, plus the file name.

How to pass the output of a command as an argument?

xargs is the best option to place output from a command into the argument of other commmand. Suppose the output of command1 is 3 and you want your next command to take this 3 as an argument so you want something like

How to save the output of one command?

FYI, if you don’t want to save the output to a file, but just view it in the terminal, use “-” instead of a filename to indicate stdout. wget also accepts stdin with the – switch. If you want to save the output in a file, use the -O switch.

Where does the output go after an exec in Bash?

After the exec, the standard output of the script as a whole goes to /some/file. I seldom use this technique; I usually use the { …; } technique instead. Note: You do have to be careful with the braces notation.