Hi,
I have a huge file & I want to add a specific text in column. But I want to add this text from a specific line number to a specific line number & another text in to another range of line numbers.
To be more specific: lets say my file has 1000 lines & 4 Columns. I want to add text "Hello"... (2 Replies)
Hi
I want to extract certain text between two line numbers like
23234234324 and
54446655567567
How do I do this with a simple sed or awk command?
Thank you.
---------- Post updated at 06:16 PM ---------- Previous update was at 05:55 PM ----------
found it:
sed -n '#1,#2p'... (1 Reply)
using sed to replace a specific string on a specific line number using variables
this is where i am at
grep -v WARNING output | grep -v spawn | grep -v Passphrase | grep -v Authentication | grep -v '/sbin/tfadmin netguard -C'| grep -v 'NETWORK>' >> output.clean
grep -n Destination... (2 Replies)
Hi guys ,
I m writing a script to delete a line at particular location.
But i m unable to use variable for specifying line number.
for example.
sed -n '7!p' filename
works fine and deletes 7th line from my file
but
sed -n '$variable!p' filename
gives following error.
sed: -e... (12 Replies)
Hello! All,
Could you please tell me how to get a specific line number from a text file?
For example below,
ABC
DEF ---> Get this line number, return to an variable
GHI
My OS is Linux.
Thank you so much for your help in advance! (3 Replies)
I have list of files in a directory 'dir'. Each file is of type HTML. I need to read each file and get the string which starts with 'http' and write them in a new text file. How can i do this shell scripting?
file1.html
<head>
<url>http://www.google.com</url>
</head>
file2.html
<head>... (6 Replies)
Hello everyone,
I don't really know anything about scripting, but I have to manage to make this script, out of necessity.
#!/bin/bash
while read -r line; do #I'm reading from a big wordlist
instructions using $line
done
Is there a way to automatically write the $line number the script... (4 Replies)
my requirement is,
consider a file output
cat output
blah sdjfhjkd jsdfhjksdh
sdfs 23423 sdfsdf sdf"sdfsdf"sdfsdf"""""dsf
hellow there
this doesnt look good
et cetc etc
etcetera
i want to replace a line of line number 4 ("this doesnt look good") with some other line
... (3 Replies)
Hi guys,
I am running a while loop in a script ro read a file line by line.
Now I want to run a grep only on the lines below the line I am that is being read by the while loop.
Eg:
If my while loop is on line 4 of the file, the grep only runs below line 4 and does not include line 1,2... (3 Replies)
Discussion started by: Junaid Subhani
3 Replies
LEARN ABOUT REDHAT
system
SYSTEM(3) Linux Programmer's Manual SYSTEM(3)NAME
system - execute a shell command
SYNOPSIS
#include <stdlib.h>
int system(const char *string);
DESCRIPTION
system() executes a command specified in string by calling /bin/sh -c string, and returns after the command has been completed. During
execution of the command, SIGCHLD will be blocked, and SIGINT and SIGQUIT will be ignored.
RETURN VALUE
The value returned is -1 on error (e.g. fork failed), and the return status of the command otherwise. This latter return status is in the
format specified in wait(2). Thus, the exit code of the command will be WEXITSTATUS(status). In case /bin/sh could not be executed, the
exit status will be that of a command that does exit(127).
If the value of string is NULL, system() returns nonzero if the shell is available, and zero if not.
system() does not affect the wait status of any other children.
CONFORMING TO
ANSI C, POSIX.2, BSD 4.3
NOTES
As mentioned, system() ignores SIGINT and SIGQUIT. This may make programs that call it from a loop uninterruptable, unless they take care
themselves to check the exit status of the child. E.g.
while(something) {
int ret = system("foo");
if (WIFSIGNALED(ret) &&
(WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
break;
}
Do not use system() from a program with suid or sgid privileges, because strange values for some environment variables might be used to
subvert system integrity. Use the exec(3) family of functions instead, but not execlp(3) or execvp(3). system() will not, in fact, work
properly from programs with suid or sgid privileges on systems on which /bin/sh is bash version 2, since bash 2 drops privileges on
startup. (Debian uses a modified bash which does not do this when invoked as sh.)
The check for the availability of /bin/sh is not actually performed; it is always assumed to be available. ISO C specifies the check, but
POSIX.2 specifies that the return shall always be non-zero, since a system without the shell is not conforming, and it is this that is
implemented.
It is possible for the shell command to return 127, so that code is not a sure indication that the execve() call failed.
SEE ALSO sh(1), signal(2), wait(2), exec(3)
2001-09-23 SYSTEM(3)