Sponsored Content
Top Forums UNIX for Dummies Questions & Answers Help required to understand a variable in shell script!!! Post 302299219 by abhishek2301 on Thursday 19th of March 2009 01:37:59 PM
Old 03-19-2009
Java Help required to understand a variable in shell script!!!

Hi,

I need to understand the following script:

a=`dirname $0`
b=`uname -s`
if [ "${a:0:1}" = "/" ] ; then
c=$a/../../../platforms/$b/extlib
else
c=`pwd`/$a/../../../platforms/$b/extlib
fi

There are a bunch of variable assignments going on here!!!
What does this variable means: "${a:0:1}"

Thanks!!!
 

10 More Discussions You Might Find Interesting

1. Linux

shell script required

Hi, iam presenting the input text file format.Of this i need the character count of the number of characters present in each file.The attached file is a combination of 3 text file.each text file starts at record 1 - 34, then the next tetx file starts. What i need is the character count of each... (1 Reply)
Discussion started by: sethunath
1 Replies

2. Shell Programming and Scripting

Shell Script Required!

Hi people, I am new to this forum. I have taken unix this semester in my college and i am new to it. I am finding shell scripting a bit hard and i need a little help. I require a shell script to delete files that end as .bak , .BAK, #, ~ and files with the name core.The Script should accept... (3 Replies)
Discussion started by: vats
3 Replies

3. Shell Programming and Scripting

Shell script help required

Hi, Can someone help me with this small piece of code. DIRNAME=$(dirname $0) BASENAME=$(basename $0) DATA="${DIRNAME}/${BASENAME}.data" && . $DATA whats is meant by && . $DATA here... Regards, Abhishek (2 Replies)
Discussion started by: max29583
2 Replies

4. Shell Programming and Scripting

shell script required...

There are two fields actually one is server name and the other one is Time. Based on time, there are 8 columns and these will be updated with the flag 1 if at all if there is any server name. Time Server name 15 to 18 18 to 21 21 to 24 00 to 03 03 to 06 06 to 09 09 to 12 Server... (3 Replies)
Discussion started by: venkatesht
3 Replies

5. Shell Programming and Scripting

Understand a old unix shell script

Hi All, I have a unix old script i but i am not able to understand the few commands in it and what it does. below is the script. if ; then for F in $(find $DIR/. ! -name . -prune -name "DP_*.dat") do IN=${F##/*/} OUT='ORD'$(echo $IN | cut -c7-) exec.ksh $IN... (2 Replies)
Discussion started by: kam786sim
2 Replies

6. Shell Programming and Scripting

help required with shell script

Hi, My input file as follws $ cat 1.txt ------- a aa aaa 11 b bb bbb 22 I am able to extract first and last column of a given line as follows. $ nawk '{print $1}' FS= RS= 1.txt | awk '{ $NF = ""; print }' a $ nawk '{print $1}' FS= RS= 1.txt | awk '{ print $NF}' 11 however, the... (4 Replies)
Discussion started by: bala123
4 Replies

7. UNIX for Dummies Questions & Answers

Shell script required

Hi, I need shell script for getting the date in format from below text output IP IS 10.238.52.65 pun-ras-bng-mhs-01#show conf port 2/4 Building configuration... Current configuration: ! card ge3-4-port 2 ! port ethernet 2/4 no shutdown encapsulation dot1q (7 Replies)
Discussion started by: surender reddy
7 Replies

8. UNIX for Dummies Questions & Answers

Need to understand shell script

Hello, Can someone please help me understand the shell script below for installing Jboss EAP 6? It is from jboss-as-standalone.sh, what does the highlighted code mean? # Load Java configuration. && . /etc/java/java.conf export JAVA_HOME Thanks! (4 Replies)
Discussion started by: learnix
4 Replies

9. UNIX for Dummies Questions & Answers

Help with understand shell script coding

Good afternoon everyone, I am very new to UNIX shell scripting and I am trying to understand the following code. I know what it does but I need to modify it so it will allow me to pass a file name as *FILENAME* Thank for any guidance offered. if ] ; then match=`expr "$file" :... (2 Replies)
Discussion started by: Walter Barona
2 Replies

10. Shell Programming and Scripting

Need help to understand the below shell script

Please help me to understand the below 3 lines of code.execute shell in jenkins 1)APP_IP=$( docker inspect --format '{{ .NetworkSettings.Networks.'"$DOCKER_NETWORK_NAME"'.IPAddress }}' ${PROJECT_NAME_KEY}"-CI" ) 2)HOST_WORKSPACE=$(echo ${WORKSPACE} | sed... (1 Reply)
Discussion started by: naresh85
1 Replies
MPI_Alloc_mem(3OpenMPI) 												   MPI_Alloc_mem(3OpenMPI)

NAME
MPI_Alloc_mem - Allocates a specified memory segment. SYNTAX
C Syntax #include <mpi.h> int MPI_Alloc_mem(MPI_Aint size, MPI_Info info, void *baseptr) Fortran Syntax (see FORTRAN NOTES) INCLUDE 'mpif.h' MPI_ALLOC_MEM(SIZE, INFO, BASEPTR, IERROR) INTEGER INFO, IERROR INTEGER(KIND=MPI_ADDRESS_KIND) SIZE, BASEPTR C++ Syntax #include <mpi.h> void* MPI::Alloc_mem(MPI::Aint size, const MPI::Info& info) INPUT PARAMETERS
size Size of memory segment in bytes (nonnegative integer). info Info argument (handle). OUTPUT PARAMETERS
baseptr Pointer to beginning of memory segment allocated. IERROR Fortran only: Error status (integer). DESCRIPTION
MPI_Alloc_mem allocates size bytes of memory. The starting address of this memory is returned in the variable base. FORTRAN NOTES
There is no portable FORTRAN 77 syntax for using MPI_Alloc_mem. There is no portable Fortran syntax for using pointers returned from MPI_Alloc_mem. However, MPI_Alloc_mem can be used with Sun Fortran compilers. From FORTRAN 77, you can use the following non-standard declarations for the SIZE and BASEPTR arguments: INCLUDE "mpif.h" INTEGER*MPI_ADDRESS_KIND SIZE, BASEPTR From either FORTRAN 77 or Fortran 90, you can use "Cray pointers" for the BASEPTR argument. Cray pointers are described further in the For- tran User's Guide and are supported by many Fortran compilers. For example, INCLUDE "mpif.h" REAL*4 A(100,100) POINTER (BASEPTR, A) INTEGER*MPI_ADDRESS_KIND SIZE SIZE = 4 * 100 * 100 CALL MPI_ALLOC_MEM(SIZE,MPI_INFO_NULL,BASEPTR,IERR) ! use A CALL MPI_FREE_MEM(A, IERR) ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ func- tions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI:Exception object. Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error. SEE ALSO
MPI_Free_mem Open MPI 1.2 September 2006 MPI_Alloc_mem(3OpenMPI)
All times are GMT -4. The time now is 12:57 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy