my input file contains thousands of lines like below
234A dept of education
9788 dept of commerce
8677 dept of engineering
How do i add a delimeter ':' after FIRST 4 CHARACTERS in a line
234A:dept of education
9788:dept of commerce
8677:dept of engineering (7 Replies)
Hello,
in my script i have this lines of code in a while cycle:
..
let j=i+1
t_prod_$i = `cat myfile.csv | grep world | cut -d ";" -f$j`
let i+=1
...
So if i try an echo $t_prod_$i at the end of the cycle i cannot see
the right value obtained by `cat myfile.csv | grep world |... (5 Replies)
Hi,
I have a variable $ID=40 and I need to build a string like
40 40 40 40 40 40
so repeating ID 'n' times separated by spaces.
Any help?
Thanks
Sarah (2 Replies)
Hi All,
I need to concatenate the values in the array into a variable. Currently the code is :
for (( i=1 ; i <= $minCount ; i++ ))
do
var="${var}""${sample_file}"
done
The output is :
/tmp/1/tmp/2/tmp/3/tmp/4/tmp/5/tmp/6/tmp/7/tmp/8/tmp/9/tmp/10
I need a space between... (1 Reply)
#! /bin/csh
set tt=12345_UMR_BH452_3_2.txt
set rr=`echo $tt | cut -d_ -f1`
set rr1=welcome
set ff=$rr $rr1
echo $ff
why $ff returned only 12345 and not 12345welcome? thanks (2 Replies)
Hi all, I'm trying to build a variable name automatically through a for loop for a script I'm working on, basically I want to build the variables named: $JVM_HOME0 or $JVM_HOME1 so that I can loop through some file copy/deletes and a server restart once completed. With the code below, I get this... (3 Replies)
Hi Team!!
Please can anyone tell me why the following line does not work properly?
str3+=$str2
it seems that str3 variable does not keep its value in order to be concatenated in the next iteration! Thus when i print the result of the line above it returns the str2 value
What i want to do is to... (8 Replies)
Hi,
I was trying to work on a file which had the following data format
1 hi
1 this
1 is
1 john
2 hello
3 test
3 case
the expected output file is the below
1 hi, this, is, john
2 hello
3 test, case
I tried using awk or while read, but I couldnt... (13 Replies)
I have a script which is migrated from AIX to Linux & now while running it is no able to concatenate string values
The string concatenation step under while loop is not displaying desired result
Please find below the piece of code:
while read EXT_FILE ; do
EXT_FILE=$EXT_FILE.ext.sent
echo... (7 Replies)
Discussion started by: PreetArul
7 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)