grep $SEARCH_STRING /etc/passwd | cut -d":" -f 1,5
I need to check the $? value of grep in the above. If I place a test for $? after the above piped command, it returns success status of grep piped to cut.
How can I get the success status of grep alone? (5 Replies)
Hi there,
I'm puzzled. Compressing the same file (same name, same md5sum) at two different times will produce a different output. I mean the md5sum of the resulting .gz files are different.
Does it make any sens to any of you?
I'd like some explanations if you know what's going on.
Thanks... (4 Replies)
Using ls input as example..
ls | sed 's/\n/ /'outputs with line breaks, where I was expecting the \n to disappear. I've tried \r as well wondering if terminal output used different breaks.
Is there a way to remove the line breaks without saving to file and then working from there?
----------... (2 Replies)
Hi All,
I have a random test file: test.txt, size: 146
$ ll test.txt
$ 146 test.txt
Take 1:
$ cat test.txt | gzip > test.txt.gz
$ ll test.txt.gz
$ 124 test.txt.gz
Take 2:
$ gzip test.txt
$ ll test.txt.gz
$ 133 test.txt.gz
As you can see, gzipping a file and piping into gzip... (1 Reply)
Hi,
I have 1 program that writes in to the STDIN of another program as shown below. Both programs contain 4 or 5 lines & would terminate in under a second.
$ driver.exe | program.exe
How is that I can attach the debugger (gdb) to program.exe ? so that I can step through and see what all... (0 Replies)
Hi
I am new to writing script and want to use a Bash Piped while-read and read from user input.
if something happens on server.log then do while loop or if something happend on user input then do while loop.
Pseudocode something like:
tail -n 3 -f server.log | while read serverline || read... (8 Replies)
Hi,
I am somewhat new to Perl and currently checking it out. I have a problem testing, if there is nothing being piped in to that script.
I am reading input from STDIN this way:
while( defined($line = <STDIN>) ) {
chomp($line);
if( $line =~ m/($ARGV)/g ) {
... (7 Replies)
Greetings!!
am trying to retrieve a particular section from the url as in url.txt..
aim is to get the 83.8 MB as output, but somehow this is not happening!, please suggest what might be wrong.. attached is the screenshot and text file of the page source.
Best Regards,
Vinu (14 Replies)
The old buffering problem again, in a very specific case. On FreeBSD this time, but it's the generic line-buffered vs fully-buffered problem.
I'm trying to pick an available bluetooth speaker (all named audio_N), by pinging all of them en mass and taking the first to respond.
The... (10 Replies)
Discussion started by: Juha Nurmela
10 Replies
LEARN ABOUT BSD
xargs
XARGS(1) General Commands Manual XARGS(1)NAME
xargs - construct argument list(s) and execute utility
SYNOPSIS
xargs [ -t ][[ -x ] -n number ][ -s size ][ utility [ arguments... ]]
DESCRIPTION
The xargs utility reads space, tab, newline and end-of-file delimited arguments from the standard input and executes the specified utility
with them as arguments.
The utility and any arguments specified on the command line are given to the utility upon each invocation, followed by some number of the
arguments read from standard input. The utility is repeatedly executed until standard input is exhausted.
Spaces, tabs and newlines may be embedded in arguments using single (`` ' '') or double (``"'') quotes or backslashes (``''). Single
quotes escape all non-single quote characters, excluding newlines, up to the matching single quote. Double quotes escape all non-double
quote characters, excluding newlines, up to the matching double quote. Any single character, including newlines, may be escaped by a back-
slash.
The options are as follows:
-n number Set the maximum number of arguments taken from standard input for each invocation of the utility. An invocation of utility will
use less than number standard input arguments if the number of bytes accumulated (see the s option) exceeds the specified size or
there are fewer than number arguments remaining for the last invocation of utility. The current default value for number is
5000.
-s size Set the maximum number of bytes for the command line length provided to utility. The sum of the length of the utility name and
the arguments passed to utility (including /dev/null terminators) will be less than or equal to this number. The current default
value for size is ARG_MAX - 2048.
-t Echo the command to be executed to standard error immediately before it is executed.
-x Force xargs to terminate immediately if a command line containing number arguments will not fit in the specified (or default)
command line length.
If no utility is specified, echo(1) is used.
Undefined behavior may occur if utility reads from the standard input.
The xargs utility exits immediately (without processing any further input) if a command line cannot be assembled, utility cannot be
invoked, an invocation of the utility is terminated by a signal or an invocation of the utility exits with a value of 255.
The xargs utility exits with a value of 0 if no error occurs. If utility cannot be invoked, xargs exits with a value of 127. If any other
error occurs, xargs exits with a value of 1.
SEE ALSO echo(1), find(1)STANDARDS
The xargs utility is expected to be IEEE Std 1003.2("POSIX") compliant.
June 6, 1993 XARGS(1)