Sponsored Content
Top Forums Programming Wrapper for unix program - urgent help needed Post 302702577 by jim mcnamara on Tuesday 18th of September 2012 02:02:01 PM
Old 09-18-2012
I think you should look at time spent in calls. gettimeofday is one of the least expensive system calls there is.

Steps to do what you asked
1. create your own shared library, call it mylib.so
You do this by writing a do-nthing call:
Code:
int gettimeofday(void *a, void *b)
{
    return 1;
}

compile it as a shared library.
2. change your environment variables:
add
Code:
    export LD_PRELOAD=/path/to/mylib.so

When you run the application it will load YOUR version of gettimeofday.
1. it may not work in secure environments like selinux because you are hijacking a syscall.
2. it will not work with setuid or setgid executables

google for LD_PRELOAD and see other examples.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

urgent help needed !!

i have a script, which is continuously looping. i want to view the script name when i use ps command... it is only showing -sh ... UID PID PPID C STIME TTY TIME COMMAND informix 8533 20923 0 18:19:28 pts/ta 0:00 -sh but i dont have my scriptname displayed .... how can i do that my script is... (0 Replies)
Discussion started by: guhas
0 Replies

2. UNIX for Dummies Questions & Answers

Unix book (urgent help needed)

hi guys i am new to UNIX and i am very much excited to learn how it works.. i was very confused with how to start and what book to follow so i went to my lecturer and asked him if he could suggest something. he advised me to get this book Your UNIX: The Ultimate Guide by "Sumitabha Das" ISBN:... (4 Replies)
Discussion started by: prabhashkashyap
4 Replies

3. Shell Programming and Scripting

urgent needed

hi i want solution regarding usage of array. i m having code which is written using if- elif and can i use or access using arrays. here i wana use array values along with if -elif condition. i dnt wana use command line argument parameter1=(scram no_scram) if ; then ... (0 Replies)
Discussion started by: manish1
0 Replies

4. UNIX for Dummies Questions & Answers

Urgent help needed to delete some text without opening the file in unix

Hi To delete some text in 2 files in line1 ( not complete line) in unix without opening the files. For example: source file is like this <?xml version="1.0"... (5 Replies)
Discussion started by: pyaranoid
5 Replies

5. UNIX for Advanced & Expert Users

Urgent help needed!!!

-------------------------------------------------------------------------------- hy guys, i got few interview questions i need someone to answer urgently: 1)If you cant get to the root, you try to fsck it, but gets errors to read file systems. What steps do you take to recover the host... (1 Reply)
Discussion started by: charneet
1 Replies

6. UNIX for Dummies Questions & Answers

Urgent Help Needed

Hello Friends, I am a Graduate in Computers. I completed BCA degree this year. I want to make my career in UNIX. But, unfortunately I don't know anybody who can guide me. I am totally confuse because I don't know where to start and what are the future prospect in UNIX. Please give your... (4 Replies)
Discussion started by: Luckyless
4 Replies

7. Shell Programming and Scripting

Urgent Help needed please

Hi, I have a small grepping problem in my script.I am having a file from which i need to make sure "#^A17" is the last updation (Next # can be ignored) before ################.The idea behind this is, if this file contains "A17" as the last updation, i need to do a particular activity. please... (7 Replies)
Discussion started by: Renjesh
7 Replies

8. Shell Programming and Scripting

How to make bash wrapper for java/groovy program with variable length arguments lists?

The following bash script does not work because the java/groovy code always thinks there are four arguments even if there are only 1 or 2. As you can see from my hideous backslashes, I am using cygwin bash on windows. export... (1 Reply)
Discussion started by: siegfried
1 Replies

9. Shell Programming and Scripting

Help needed on wrapper script

Hi Gurus, I need to build a wrapper script which will be passing the loading date and the data file name (provides option to the user to load a single data file or load all the data files) to the actual loader data_load.ksh to load in the database. 1. I want to execute the loader script... (6 Replies)
Discussion started by: express14
6 Replies

10. Programming

Urgent help needed.. C++ program to convert decimal to hexa decimal

Hi , seq can be 0...128 int windex = seq / 8; int bindex = seq % 8; unsigned char bitvalue = '\x01' << (7-bindex) ; bpv.bitmapvalue = bitvalue; This is the part of a program to convert decimal to bitmap value of hexadecimal. I want this to change to convert only to... (1 Reply)
Discussion started by: greenworld123
1 Replies
gettimeofday(2) 						System Calls Manual						   gettimeofday(2)

NAME
gettimeofday - get the date and time SYNOPSIS
DESCRIPTION
The function obtains the current time, expressed as seconds and microseconds since Epoch, and stores it in the structure pointed to by tp. The resolution of the system clock is one microsecond. PARAMETERS
Programs should use this time zone information only in the absence of the environment variable. tp A pointer to a structure in which the current time is returned. The structure includes the following members: tzp If this parameter is not a null pointer, it is interpreted as a pointer to a structure under HP-UX. The structure has the following fields: tz_minuteswest The number of minutes that the local time zone is west of Coordinated Universal Time (UTC) or Epoch. tz_dsttime A flag that, if nonzero, indicates that Daylight Savings Time (DST) applies locally during the appropriate part of the year. RETURN VALUE
returns the following values under HP-UX: Successful completion. Failure. is set to indicate the error. ERRORS
If fails, is set to the following value under HP-UX: [EFAULT] An argument address referenced invalid memory. EXAMPLES
The following HP-UX example calls twice. It then computes the lapsed time between the calls in seconds and microseconds and stores the result in a timeval structure: WARNINGS
Relying on a granularity of one microsecond may result in code that is not portable to other platforms. AUTHOR
was developed by the University of California, Berkeley, and HP. SEE ALSO
date(1), ftime(2), settimeofda(2), stime(2), time(2), ctime(3C). gettimeofday(2)
All times are GMT -4. The time now is 08:37 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy