io_waitread(3) Library Functions Manual io_waitread(3)NAME
io_waitread - read from a descriptor
SYNTAX
#include <io.h>
int io_waitread(int64 fd,char* buf,int64 len);
DESCRIPTION
io_waitread tries to read len bytes of data from descriptor fd into buf[0], buf[1], ..., buf[len-1]. (The effects are undefined if len is 0
or smaller.) There are several possible results:
o o_waitread returns an integer between 1 and len: This number of bytes was available for immediate reading; the bytes were read into the
beginning of buf. Note that this number can be, and often is, smaller than len; you must not assume that io_waitread always succeeds in
reading exactly len bytes.
o io_waitread returns 0: No bytes were read, because the descriptor is at end of file. For example, this descriptor has reached the end of
a disk file, or is reading an empty pipe that has been closed by all writers.
o io_waitread returns -3, setting errno to something other than EAGAIN: No bytes were read, because the read attempt encountered a persis-
tent error, such as a serious disk failure (EIO), an unreachable network (ENETUNREACH), or an invalid descriptor number (EBADF).
SEE ALSO io_nonblock(3), io_waitread(3), io_waitreadtimeout(3)io_waitread(3)
Check Out this Related Man Page
io_tryread(3) Library Functions Manual io_tryread(3)NAME
io_tryread - read from a descriptor without blocking
SYNTAX
#include <io.h>
int io_tryread(int64 fd,char* buf,int64 len);
DESCRIPTION
io_tryread tries to read len bytes of data from descriptor fd into buf[0], buf[1], ..., buf[len-1]. (The effects are undefined if len is 0
or smaller.) There are several possible results:
o o_tryread returns an integer between 1 and len: This number of bytes was available for immediate reading; the bytes were read into the
beginning of buf. Note that this number can be, and often is, smaller than len; you must not assume that io_tryread always succeeds in
reading exactly len bytes.
o io_tryread returns 0: No bytes were read, because the descriptor is at end of file. For example, this descriptor has reached the end of
a disk file, or is reading an empty pipe that has been closed by all writers.
o io_tryread returns -1, setting errno to EAGAIN: No bytes were read, because the descriptor is not ready. For example, the descriptor is
reading an empty pipe that could still be written to.
o io_tryread returns -3, setting errno to something other than EAGAIN: No bytes were read, because the read attempt encountered a persis-
tent error, such as a serious disk failure (EIO), an unreachable network (ENETUNREACH), or an invalid descriptor number (EBADF).
io_tryread does not pause waiting for a descriptor that is not ready. If you want to pause, use io_waitread or io_wait.
You can make io_tryread faster and more efficient by making the socket non-blocking with io_nonblock().
SEE ALSO io_nonblock(3), io_waitread(3), io_tryreadtimeout(3)io_tryread(3)
Hi All,
These are the two ways i tried to read file but i getting work with second one not with the first.
char buf; // Defining space for buf
ctrlfnum = fopen(filename_arr.control_fname,"r");
1) n = fread(buf,sizeof(buf),1,ctrlfnum); ============== (not works)
2) n =... (4 Replies)
I'm attempting to extract lines from a file where column lengths are fixed, e.g col1 len=5 col2 len=6...
However if I do something like
cat file |while read ans
do
...
The padding between each column is reduced to a space, is there an easy way to read the file with the original column... (3 Replies)
Hello, I am a newbie to Unix! I am having a problem trying to read in multiple values and constructing a copy command. It will work when reading in only 1 value from a file (testdata1), but there's an error when attempting to code for multiple values per line. Below are my 2 examples.
This... (2 Replies)
Recently my project needs int64 variables. However my os and computer are both 32bits.
So how can i use int64 as a parameter in a function.
and is int64 a structure as user-defined structures.....
???
thanx
i am waiting for ur answer:rolleyes: (2 Replies)
I have an array of distances and a len, for example
len = 323
dist =
I want to calculate the start and end index values around each distance in the array with a length of len from it. Values in dist are stored in ascending order. (4 Replies)
Hello to all,
I would like to search sequences of bytes inside big binary file.
The bin file contains blocks of information, each block begins is estructured as follow:
1- Each block begins with the hex 32 (1 byte) and ends with FF. After the FF of the last block, it follows 33.
2- Next... (59 Replies)
awk '{if(len==0){last=$4;total=$6;len=1;getline}if($4!=last){printf("%s\t%f\n", last, total/len);last=$4;total=$6;len=1}else{total+=$6;len+=1}}END{printf("%s\t%f\n", last, total/len)}' exon.txt > output.txt
In the attached file I am just trying to group all the same names in column $4 and then... (2 Replies)