Without seeing util.c I can't know what it's using gets for. gets reads a string from standard input, storing it as a character array terminated by a NULL character.
The problem with gets is that it takes an unlimited amount of input. It does not know how much space is available in the buffer. For instance:
If I typed "486193474587130958712057190856714890651618476" and hit enter, it would dump that entire string into that buffer of 16 bytes, which obviously isn't large enough to hold it. The remainder of it would get crammed into whatever bytes of memory trail after the buffer, which may be unused, or used for other variables, or part of the call stack, etc. When overflows like this happen they can be VERY hard to debug since by nature buffer overflows overwrite memory they're not supposed to. It's also a security risk -- if someone knows there's a buffer they can overflow, they can write to variables after it in memory, setting them to whatever values they want!
This is much safer:
This will not overflow the buffer, it will only read a maximum of 15 bytes.
Hey guys, need some help. Running AIX Version 5.2 and one of our cron jobs is writing errors to a log file. Any ideas on the following error message.
Error: Internal system error: Unable to initialize standard output file
I'm guessing more info might be needed, so let me know.
Thanks (2 Replies)
hi there
i write one awk script file in shell programing
the code is related to dd/mm/yy to month, day year format
but i get an error
please can anybody help me out in this problem ??????
i give my code here including error
awk `
# date-month -- convert mm/dd/yy to month day,... (2 Replies)
I encounters a VSIFAX related error:
vfxstat: Cannot login to server on rsac3: Connect error to host 172.16.1.45: Invalid argument
It started happening last night with a core dump. Then we can't start VSIFAX again.
I am runing VSI-FAX 4.2 on AIX box (0 Replies)
--------------------------------------------------------------------------------
Hello, help me please.
I am trying to create a mksysb bakup using nim. I am geting this error, how to correct it ? :
Command : failed stdout: yes stderr: no... (9 Replies)
Hi Guys.
This is part of my filesystem structure :
Filesystem size used avail capacity Mounted on
/dev/md/dsk/d0 47G 5.2G 42G 12% /
/devices 0K 0K 0K 0% /devices
ctfs 0K 0K 0K 0% ... (2 Replies)
Hi - I am getting the error
`Error reading response length from authentication socket'
when I ssh from my cluster to another cluster, and then back to my cluster. It doesn't seem to affect anything, but it's just annoying that it always pops up and tends to confuse new users of the cluster. I... (1 Reply)
im kinda new to shell scripting so i need some help
i try to run this script and get the error code
> 5 ")syntax error: operand expected (error token is "
the code for the script is
#!/bin/sh
#
# script to see if the given value is correct
#
# Define errors
ER_AF=86 # Var is... (4 Replies)
what is this error log = hda: irq timeout: error=0x00 and how to solve?
every day upon checking the logs i see this error.
hda: irq timeout: error=0x00
hda: irq timeout: error=0x00
hda: irq timeout: error=0x00
hda: irq timeout: error=0x00
hw_client: segfault at 0000000000000046 rip... (3 Replies)
I have two servers with a fresh install of Solaris 11, and having problems when doing rpcinfo between them. There is no firewall involved, so everything should theoretically be getting through. Does anyone have any ideas? I did a lot of Google searches, and haven't found a working solution yet.
... (2 Replies)
I am writing a shell script with 2 run time arguments. During the execution if i got any error, then it needs to redirected to a error file and in console. Also both error and output to be redirected to a log file. But i am facing the below error.
#! /bin/sh
errExit ()
{
errMsg=`cat... (1 Reply)
Discussion started by: sarathy_a35
1 Replies
LEARN ABOUT SUNOS
setbuf
setbuf(3C) Standard C Library Functions setbuf(3C)NAME
setbuf, setvbuf - assign buffering to a stream
SYNOPSIS
#include <stdio.h>
void setbuf(FILE *stream, char *buf);
int setvbuf(FILE *stream, char *buf, int type, size_t size);
DESCRIPTION
The setbuf() function may be used after the stream pointed to by stream (see intro(3)) is opened but before it is read or written. It
causes the array pointed to by buf to be used instead of an automatically allocated buffer. If buf is the null pointer, input/output will
be completely unbuffered. The constant BUFSIZ, defined in the <stdio.h> header, indicates the size of the array pointed to by buf.
The setvbuf() function may be used after a stream is opened but before it is read or written. The type argument determines how stream
will be buffered. Legal values for type (defined in <stdio.h>) are:
_IOFBF Input/output to be fully buffered.
_IOLBF Output to be line buffered; the buffer will be flushed when a NEWLINE is written, the buffer is full, or input is
requested.
_IONBF Input/output to be completely unbuffered.
If buf is not the null pointer, the array it points to will be used for buffering, instead of an automatically allocated buffer. The size
argument specifies the size of the buffer to be used. If input/output is unbuffered, buf and size are ignored.
For a further discussion of buffering, see stdio(3C).
RETURN VALUES
If an illegal value for type is provided, setvbuf() returns a non-zero value. Otherwise, it returns 0.
USAGE
A common source of error is allocating buffer space as an "automatic" variable in a code block, and then failing to close the stream in the
same block.
When using setbuf(), buf should always be sized using BUFSIZ. If the array pointed to by buf is larger than BUFSIZ, a portion of buf will
not be used. If buf is smaller than BUFSIZ, other memory may be unexpectedly overwritten.
Parts of buf will be used for internal bookkeeping of the stream and, therefore, buf will contain less than size bytes when full. It is
recommended that stdio(3C) be used to handle buffer allocation when using setvbuf().
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO fopen(3C), getc(3C), malloc(3C), putc(3C), stdio(3C), attributes(5), standards(5)SunOS 5.10 14 Aug 2002 setbuf(3C)