Sponsored Content
Full Discussion: $(< file ) and $( cat file )
Top Forums Shell Programming and Scripting $(< file ) and $( cat file ) Post 303012659 by bakunin on Wednesday 7th of February 2018 10:56:12 AM
Old 02-07-2018
Quote:
Originally Posted by jlliagre
Code:
$(< file1 file2)

Using more than one redirection lead to undefined behavior.
Perhaps this is just an aside, but wouldn't redirecting from a named pipe work? That is, if in $(< file1) file1 would be a named pipe being filled by cat file1 file2 ... ?

And second, wouldn't $(< $(cat file1 file2) ) also work? Right now i am travelling with this damn work-laptop and have no U*X-system at hand, so i can only speculate instead of trying....

bakunin
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

cat and lp or pr printing of file

Can you use cat to send the first 25 lines of a file to the printer? I'm thinking I can pipe it with '|' but I'm not school to check printer output. With the 'nl' used, all lines are numbered on the print out, but how does one number only the blank lines? Thanks:) (1 Reply)
Discussion started by: bitwize
1 Replies

2. Shell Programming and Scripting

cat file problem

Hi, I wnat to read a fiel line by line and store each line in a variabel, so I made a for loop: for i in `cat file` ; do #do sth. done; The problem is, that in the file, there are lines with only asterisks like this... (3 Replies)
Discussion started by: bensky
3 Replies

3. UNIX for Dummies Questions & Answers

Easiest way to cat out first 100 lines of a file into a different file?

Not sure how to do this exactly.. just want to take the first 100 lines of a file and cat it out into a second file. I know I can do a more on a file and > it into a different file, but how can I make it so only the first 100 lines get moved over? (1 Reply)
Discussion started by: LordJezo
1 Replies

4. UNIX for Dummies Questions & Answers

How to cat file

I want to cat a file with only show the line contain '/bin/bash' but don't show the line contain 'load' (don't show if the line contain 'load' and '/bin/bash' together), how to type in the command? thk a lot! (2 Replies)
Discussion started by: zp523444
2 Replies

5. Shell Programming and Scripting

Cat all yesterdays file into one file?

I am looking for a command to take files with a specific date and cat them all into big file. I know I can use commands to list all of the files from a certain date. But I want to do that and take those files and make on large files containing all of them. Any help would be great. This is being... (1 Reply)
Discussion started by: Jcheetwood
1 Replies

6. Shell Programming and Scripting

split a line of a file and cat a file with another

Hi, I have two files one.txt laptop boy apple two.txt unix linux OS openS I want to split one.txt into one line each and concatenate it with the two.txt output files onea.txt laptop (4 Replies)
Discussion started by: avatar_007
4 Replies

7. Shell Programming and Scripting

Cat file

how to cat a file by ignoring first line and last line (1 Reply)
Discussion started by: thelakbe
1 Replies

8. UNIX for Advanced & Expert Users

cat can not open file

Hi All, I have stumbled upon very unique issue. In my script I am doing cat file and then greping and cutting so as to assign the value to variable. My file is, <mxc_tl_load_extractdata_prop.bsh> DB_USER=test_oper hostname=xxx FTP_USER=test1_operate MAIL_LIST=xxx@yyy.com... (1 Reply)
Discussion started by: paragd
1 Replies

9. UNIX for Advanced & Expert Users

for i in `cat file` do

in bash: for i in `cat file` ; do echo $i done; how will i do this in perl ? (10 Replies)
Discussion started by: linuxgeek
10 Replies

10. Shell Programming and Scripting

Ssh cat file output into a file on local computer

Hello, I'm on a remote computer by SSH. How can I get the output of "cat file" into a file on the local computer? I cannot use scp, because it's blocked. something like: ssh root@remote_maschine "cat /file" > /locale_machine/file :rolleyes: (2 Replies)
Discussion started by: borsti007
2 Replies
comm(1) 							   User Commands							   comm(1)

NAME
comm - select or reject lines common to two files SYNOPSIS
comm [-123] file1 file2 DESCRIPTION
The comm utility reads file1 and file2, which must be ordered in the current collating sequence, and produces three text columns as output: lines only in file1; lines only in file2; and lines in both files. If the input files were ordered according to the collating sequence of the current locale, the lines written will be in the collating sequence of the original lines. If not, the results are unspecified. OPTIONS
The following options are supported: -1 Suppresses the output column of lines unique to file1. -2 Suppresses the output column of lines unique to file2. -3 Suppresses the output column of lines duplicated in file1 and file2. OPERANDS
The following operands are supported: file1 A path name of the first file to be compared. If file1 is -, the standard input is used. file2 A path name of the second file to be compared. If file2 is -, the standard input is used. USAGE
See largefile(5) for the description of the behavior of comm when encountering files greater than or equal to 2 Gbyte ( 2^31 bytes). EXAMPLES
Example 1 Printing a list of utilities specified by files If file1, file2, and file3 each contain a sorted list of utilities, the command example% comm -23 file1 file2 | comm -23 - file3 prints a list of utilities in file1 not specified by either of the other files. The entry: example% comm -12 file1 file2 | comm -12 - file3 prints a list of utilities specified by all three files. And the entry: example% comm -12 file2 file3 | comm -23 -file1 prints a list of utilities specified by both file2 and file3, but not specified in file1. ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of comm: LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES, and NLSPATH. EXIT STATUS
The following exit values are returned: 0 All input files were successfully output as specified. >0 An error occurred. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWesu | +-----------------------------+-----------------------------+ |CSI |enabled | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
cmp(1), diff(1), sort(1), uniq(1), attributes(5), environ(5), largefile(5), standards(5) SunOS 5.11 3 Mar 2004 comm(1)
All times are GMT -4. The time now is 02:31 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy