11-25-2008
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi everyone,
I have a Linux OS in my PC (older version 9). Its default shell is bash. Whenever I try to run some Perl program it throws error ! eg, if I run this simple PERL program ,
#!/usr/bin/perl
printf "\lHello \n";
$var=3 ;
printf $var;
@list=(1,2,3);
printf "@list";... (6 Replies)
Discussion started by: adc22
6 Replies
2. UNIX for Dummies Questions & Answers
Hey all,
I need to know how many lines of C code are in a source bundle. I have extracted the bundle and hence there is a big directory tree with C files everywhere.
So far I have something like:
find . -name "*.c" | grep \ ./*/*/*/*/*/*
obviously wrong, if someone could help me out... (3 Replies)
Discussion started by: zigga15
3 Replies
3. Shell Programming and Scripting
Hi all. Suppose I have the following function in an executable file named "HOLA":
------------------------
function hola { echo "Hola ${@}."; }
------------------------
In addition, suppose that I want to execute the file so I can input my name next to ./HOLA. I mean,... (4 Replies)
Discussion started by: hresquivelo
4 Replies
4. Shell Programming and Scripting
I'm trying to set up an alias in .bash_aliases to show just the filenames of the files in a directory, which the following command will do:
ls -l | grep ^- | awk '{print $NF}'
kjb.zip
ap.zip
tor.zip
However when I set up the following alias in .bash_aliases:
alias lf="ls -l | grep ^- |... (16 Replies)
Discussion started by: gencon
16 Replies
5. UNIX for Dummies Questions & Answers
Hello all,
Something strange going on with a shell script I'm writing. It's trying to write a list of files that it finds in a given directory to another file. But I also have a skip list so matching files that are in that skip list should be, well uhm, skipped :)
Here's the code of my... (2 Replies)
Discussion started by: StijnV
2 Replies
6. UNIX for Dummies Questions & Answers
I have simple script. like that, I am working on /usr/local/src and also under src folder there is a ft folder
#!/bin/ksh
#!/bin/bash
dirpath="/usr/local/src/ft"
echo $dirpath
cd $dirpath
echo displays ok "/usr/local/src/ft"
but that doesn't enter "ft" folder. stays in current... (4 Replies)
Discussion started by: F@NTOM
4 Replies
7. Shell Programming and Scripting
why, when i run my shell with sh command it run without problem, but when run with nohup nombreshell.sh $ command not run correctly... values obtained from database are not displayed in the csv file.
My shell do that:
1° data base access with sqlplus:
read_sql_stmt() {
typeset stmt=$1... (3 Replies)
Discussion started by: joaco
3 Replies
8. UNIX for Dummies Questions & Answers
Hi All,
i created the below script to move file with xml extension from one directory to another,but the mv command is not working inside the shell script,
#!/us/bin/ksh
filepath="/apps/extract"
filename="*.xml"
foldername=2191POB000_$(date +%Y%m%d%H%M%S)
mkdir -p "$filepath/$foldername"... (3 Replies)
Discussion started by: Radhas
3 Replies
9. UNIX for Dummies Questions & Answers
Options::
A)$shell
B)echo $ bash
C)echo $ O
D)$ O (1 Reply)
Discussion started by: raghugowda
1 Replies
10. Programming
I want copy Files:
But cp don't work:
shell_exec("cp ".$pfad." ".$genzone);
shell_exec("cp ../Chrysanthemum.jpg ../test");
Whats wrong? (3 Replies)
Discussion started by: Linuxmann
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)