To keep the code concise ( as is ), in bash or the shell of your preference, you can do ...
Or if you want a pure perl script, then every step of that compact code will simply be spelled out in more detail ( a bit longer ), I can post it if you needed.
I would really appreciate that .. It would be great for future reference.
How would I write a command(s) to read from a file (list) that looks like this: 29847374384 and grep from a second file (list) that looks like this: 29847374384, jkdfkjdf,3833,ddd:confused: (1 Reply)
Hi, is there a bullet proof of getting the history of all commands entered by a user on a specific server and idealy with the times ?
We have several servers. Therefore we can simply logon to one and do RLOGINS to go to others. We always first logon to servers with our personnal login and then... (4 Replies)
I have one base file, and multiple target files-- each have uniform line structure so no need to use grep to find things-- can just define sections by line number.
My question is quite simple-- can I use sed to copy a defined block of lines (say lines 5-10) from filename1.txt to overwrite an... (3 Replies)
Dear all,
I have a file like below. I want to replace all the '.' in the 3rd column with 'NA'. I don't know how to do that. Anyone has an iead? Thanks a lot!
8 70003200 21.6206
9 70005700 17.5064
10 70002200 .
11 70005100 19.1001
17 70008000 16.1970
32 70012400 26.3465
33... (9 Replies)
My need is :
Want to change
docBase="/something/something/something"
to
docBase="/only/this/path/for/all/files"
I have some (about 250 files)xml files.
In FileOne it contains
<Context path="/PPP" displayName="PPP" docBase="/home/me/documents" reloadable="true" crossContext="true">... (1 Reply)
Hi,
I am trying to use sed to replace a file path within all the .lay (.txt) files in a folder. I feel that this should be easy but I can't get it to work no matter what i try.
I'm using cygwin.
For a .txt file containing the below line I want to replace this file path with a new one.
... (1 Reply)
Hi,
I tried below method;
mv -v /oracle1/scr/tilki/willsendtilkiNew/VOICE-MO_$nfname.gz \
$(echo /oracle1/scr/tilki/willsendtilkiNew/VOICE-MO_$nfname.gz | tr 'dat' 'txt');
nfame variable has the string "dat" .
I need to rename files like below;
ASIS: 20140902103700_100319.dat.gz... (8 Replies)
Hi dears
i have text file like this:
INPUT.txt
001_1_173 j nuh ]az
001_1_174 j ]esma. nuh ]/.xori
.
.
. and have another text
like this
TABLE.txt
j j
nuh word1... (6 Replies)
Hi I want to read a text file and replace various number of spaces between each string in to a single "," or any other character .Please let me know the command to do so. My input file is a txt file which is the output of a SQL table extract so it contains so many spaces between each column of the... (2 Replies)
Discussion started by: Hari Prasanth
2 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)