Hi,
Let me explain the situation.
There are many files in a directory and its sub-directories that conatin the string pattern "pa". I want to replace all such instances with the pattern "pranavagarwal"
doing a
grep "pa" `ls`
does give me all the instances of the occurence of that... (3 Replies)
Dear all,
I have the following problem (it originates in the domain of bio-inf, but it is a general problem).
I have two files of one column each and of different length: a.txt and b.txt.
a.txt contains alphanumeric strings (around 30 digit) and there are 300 rows
b.txt contains alphanumeric... (2 Replies)
I need to search and replace a particular string in a file. Only the exact match of the string should be replaced.
eg: File contents : abc abcd abcdef
--> Replace only 'abc' with 'xyz', but it should not replace abcd with xyzd.
So the o/p should be: xyz abcd abcdef.
How can this be done? I... (5 Replies)
Hi,
What should be the syntax to match and replace an exact string using sed? And not replacing any string that contain the value?
Eg.
testtest
etstetst
testetst
testtttt
etsttest
testtesttest
testtest
I only want to replace the line with exact string "testtest" with "123456"
... (2 Replies)
Hey everybody. I've got a simple problem but am unsure how to resolve it. I am using a script to edit multiple files at once. Inside the script I am using an sed command to make the changes. My problem is that I can only get it to work for stings that contain a word or words. How can I modify it to... (1 Reply)
Hi,
I need to use the regex in the replacement string in SED command.
something like
sed -e ' s/\(^\{5\}\).\{150\}\(.*\)$/\10\{30\}1\{30\}A\{60\}B\{30\}\2/' abc
which means for all the lines in file abc that starts with 5 characters, I need to replace character 6-151... (6 Replies)
Dear Unix Forum Group Members,
Please do let me know how I can replace the double pipe with single pipe recursively on single record.
Sample Input Data:
DN set|Call prefix||| Called number address nature
0||| *789|||||||ALL number types
0||| 00||||||||ALL number types
10||... (5 Replies)
I want to replace a string by contents of file.
I am trying the following sed command:
cat sample | sed "s^<enter description here>^`cat details`^"
But it is not working.
a=`cat details` and using $a will not help since it will affect the whitespaces.
What am I missing in the above sed... (5 Replies)
Hello,
Just surfed on the web for probable answers but could not get them working.
I wish to replace the string containing spaces by another phrase but below answers did not work.
My string is:
PAIN & GAIN
I wish to convert it to:
P&G
I just need it working with sed with function -i
... (6 Replies)
Discussion started by: baris35
6 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)