how can i correct it?, even when i write values to the file, i cannot open it manually, it says it not readable
this time when wanna start reading, the open() returns -1
Hi gurus
I am not a C programmer but I need to read and write files on a computer on LAN using IP address.
Suppose on a computer that has an IP 192.168.0.2
Any help or code example. I did in JAVA using URL, but do not know how to do in ANSI-C.
In java:
-------
URL url = new... (3 Replies)
Hi my prob statement is to create a new file or to append to the 1tst file the followign chages.
File 1: txt file.
portfolio No a b c d
abc 1 Any Any Any charString
cds 2 values values values charString
efd 3 can can can charString
fdg 4 come come come charString... (4 Replies)
Hi all,
I have the following shell script code which tries to sftp and writes the log into the log file.
TestConnection ()
{
echo 'Connection to ' $DESTUSERNAME@$DESTHOSTNAME
$SETDEBUG
if ]; then rm $SCRIPT ; fi
touch $SCRIPT
echo "cd" $REMOTEDIR >> $SCRIPT
echo "quit" >>... (10 Replies)
Hello everybody,
I'm trying to code a program which makes the following:
It sends an ARP request frame and when it gets the reply, extracts the IP address of source and writes it to a .txt file. This is gonna be done with many hosts (with a for() loop), so, the text file would look like... (2 Replies)
Hi All,
Please help me in writing data to a file in one row.
In database there is a column which contains large data which does not fit in the file in one row. The column contains list of paths. I want to write these paths to a file in one row.
Please find the code below writes :
... (2 Replies)
Need to develop a unix shell script for the below requirement and I need your assistance:
1) search for file.log and file.bad file in a directory and read them
2) pull out "Load_Start_Time", "Data_File_Name", "Error_Type" from log file
4) concatinate each row from bad file as... (3 Replies)
Hi
I am trying to extract information out of a file but keep getting grep cant open errors
the code is below:
#bash
#extract orders with blank address details
#
# obtain the current date
# set today to the current date ccyymmdd format
today=`date +%c%m%d | cut -c24-31`
echo... (8 Replies)
Hi All,
Here is my requirement. I am grepping through the log files and cutting some fields from the file to generate a csv file. Now I have to check if 2nd field is having some fixed value then with the help of 4th field I have to look in same log and run another grep command to retrieve the... (11 Replies)
I have a file like this,
1,a,saurav
2,b,rout
I want to show this file in a perl cgi page table and want to add a column which will contain a text box. There I will give some manual input, which will be written to the existing file(or a new file) in below format.
1|a|saurav|bangalore... (2 Replies)
Hello all
As part of my TUI - (line based) Text User Interface, i do have 2 commands to assist working with conf files.
Now, for me they work, but since i wrote them, i automaticly use them they way they should be used... you know what i mean. ;)
Anyway, they are designed to read 'simple'... (3 Replies)
Discussion started by: sea
3 Replies
LEARN ABOUT PLAN9
open
OPEN(2) System Calls Manual OPEN(2)NAME
open, create, close - open a file for reading or writing, create file
SYNOPSIS
#include <u.h>
#include <libc.h>
int open(char *file, int omode)
int create(char *file, int omode, ulong perm)
int close(int fd)
DESCRIPTION
Open opens the file for I/O and returns an associated file descriptor. Omode is one of OREAD, OWRITE, ORDWR, or OEXEC, asking for permis-
sion to read, write, read and write, or execute, respectively. In addition, there are three values that can be ORed with the omode: OTRUNC
says to truncate the file to zero length before opening it; OCEXEC says to close the file when an exec(2) or execl system call is made; and
ORCLOSE says to remove the file when it is closed (by everyone who has a copy of the file descriptor). Open fails if the file does not
exist or the user does not have permission to open it for the requested purpose (see stat(2) for a description of permissions). The user
must have write permission on the file if the OTRUNC bit is set. For the open system call (unlike the implicit open in exec(2)), OEXEC is
actually identical to OREAD.
Create creates a new file or prepares to rewrite an existing file, opens it according to omode (as described for open), and returns an
associated file descriptor. If the file is new, the owner is set to the userid of the creating process group; the group to that of the
containing directory; the permissions to perm ANDed with the permissions of the containing directory. If the file already exists, it is
truncated to 0 length, and the permissions, owner, and group remain unchanged. The created file is a directory if the CHDIR bit is set in
omode. It is an exclusive-use file if the CHEXCL bit is set. Such files may be open for I/O by only one client at a time, but the file
descriptor may become invalid if no I/O is done for an extended period; see open(5).
Create fails if the path up to the last element of file cannot be evaluated, if the user doesn't have write permission in the final direc-
tory, or if the file already exists and does not permit the access defined by omode. If the file is new and the directory in which it is
created is a union directory (see intro(2)) then the constituent directory where the file is created depends on the structure of the union:
see bind(2).
Close closes the file associated with a file descriptor. Provided the file descriptor is a valid open descriptor, close is guaranteed to
close it; there will be no error. Files are closed automatically upon termination of a process; close allows the file descriptor to be
reused.
SOURCE
/sys/src/libc/9syscall
SEE ALSO intro(2), bind(2), stat(2)DIAGNOSTICS
These functions set errstr.
OPEN(2)