Hi folks,
I am wondering how to output awk back to a variable.
I am new to Unix/Linux.
I am trying to get rid of a decimal number and put the output back in a variable for further use in the script. here is how I used awk:
var=$1
echo $var |awk '{print $1 *100}' | $var
echo $var
this... (4 Replies)
I wanna use a system function to deal with several data. So I use awk variable FILENAME to transfer the file directory to system command, but it does not work.
I use a shell function "out_function" to deal with data and save the result in another directory with the same file name.
How can I... (2 Replies)
Hi
I am trying to store the output of awk into a variable in a shell script. I can run it successfully from the command line but not from a ksh shell script.
ls -al test.txt | grep -v grep | awk '{print $1}'
returns -rw-r--r--
#!/bin/ksh
perm=$(`ls -al test.txt | grep -v grep | awk... (2 Replies)
Not sure why it is not working the following :
set -- $@
stype ="a"
for shell_args in "$@"
do
$stype=` awk '{print substr ("'"$shell_args"'", 0, 3)}' `
echo $stype
done
Thank you (5 Replies)
hello,
I want to print my output into a file inside of awk, but I don't know it could wokr with using system (piping the $1-4 to another shellskript):
cat file.txt |awk '{ if ($5==2) {dataname=$1 "_" $2 "_" $3 "_" $4 "_typing.rad"
befehl=".gen_test " $7 " " $8 " " $8
system(befehl) >... (5 Replies)
Hi everybody,
I am working on a bigger awk script in which one part is comparing the size of two files.
I want to evaluate which file is bigger and then just save the bigger one.
I got it all working except for the part where I want to figure out which file is bigger; the one awk is currently... (2 Replies)
Hi all,
Hope someone can help me out here.
I have this BASH script (see below)
My problem lies with the variable path.
The output of the command find will give me several fields. The 9th field is the path. I want to captured that and the I want to filter this to a specific level.
The... (6 Replies)
hi i want to find the size of a folder and assign it to a variable and then compare if it is greater than 1 gb.
i am doin this script, but it is throwing error....
#!/bin/ksh
cd . | du -s | size = awk '{print $1}'
if size >= 112000
then
echo size high
fi
ERROR : (4 Replies)
I am reasonably capable with awk and its quirks, but not with shell weirdness. This has to be Bourne Shell for portability reasons. I have an awk program that is working just fine; it handles multiple input streams and produces several reports, based on the request (-v Variables). In addition... (3 Replies)
Hi,
I am trying to use variable output in awk to append a string to a word in a line. But that is not happening. Could you please help me on this.
YouTube Video Tutorial: How to Use Code Tags and Format Posts @UNIX.com
The below is the code
#!/bin/ksh
set -x
src=/users/oracle/Temp... (2 Replies)
Discussion started by: pvmanikandan
2 Replies
LEARN ABOUT OSX
popen
POPEN(3) BSD Library Functions Manual POPEN(3)NAME
pclose, popen -- process I/O
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h>
FILE *
popen(const char *command, const char *mode);
int
pclose(FILE *stream);
DESCRIPTION
The popen() function ``opens'' a process by creating a bidirectional pipe, forking, and invoking the shell. Any streams opened by previous
popen() calls in the parent process are closed in the new child process. Historically, popen() was implemented with a unidirectional pipe;
hence, many implementations of popen() only allow the mode argument to specify reading or writing, not both. Because popen() is now imple-
mented using a bidirectional pipe, the mode argument may request a bidirectional data flow. The mode argument is a pointer to a null-termi-
nated string which must be 'r' for reading, 'w' for writing, or 'r+' for reading and writing.
The command argument is a pointer to a null-terminated string containing a shell command line. This command is passed to /bin/sh, using the
-c flag; interpretation, if any, is performed by the shell.
The return value from popen() is a normal standard I/O stream in all respects, save that it must be closed with pclose() rather than
fclose(). Writing to such a stream writes to the standard input of the command; the command's standard output is the same as that of the
process that called popen(), unless this is altered by the command itself. Conversely, reading from a ``popened'' stream reads the command's
standard output, and the command's standard input is the same as that of the process that called popen().
Note that output popen() streams are fully buffered, by default.
The pclose() function waits for the associated process to terminate; it returns the exit status of the command, as returned by wait4(2).
RETURN VALUES
The popen() function returns NULL if the fork(2) or pipe(2) calls fail, or if it cannot allocate memory.
The pclose() function returns -1 if stream is not associated with a ``popened'' command, if stream already ``pclosed'', or if wait4(2)
returns an error.
ERRORS
The popen() function does not reliably set errno.
SEE ALSO sh(1), fork(2), pipe(2), wait4(2), fclose(3), fflush(3), fopen(3), stdio(3), system(3)BUGS
Since the standard input of a command opened for reading shares its seek offset with the process that called popen(), if the original process
has done a buffered read, the command's input position may not be as expected. Similarly, the output from a command opened for writing may
become intermingled with that of the original process. The latter can be avoided by calling fflush(3) before popen().
Failure to execute the shell is indistinguishable from the shell's failure to execute command, or an immediate exit of the command. The only
hint is an exit status of 127.
The popen() function always calls sh(1), never calls csh(1).
HISTORY
A popen() and a pclose() function appeared in Version 7 AT&T UNIX.
Bidirectional functionality was added in FreeBSD 2.2.6.
BSD May 3, 1995 BSD