When an invalid character is entered the code goes into an endless loop. It seems this line:
Is essentially the same as this:
It may check the condition, but in this case that condition will never change. You could that same check in an if statement so it is only checked once. Or use the while(1) in that loop with breaks to jump out of the loop when needed. You might want to look into fgets. The scanf function is great for learning, but can introduce potential security problems. Hope that helps.
hi,
how does a program know whether some data are available from stdin?
I would like to make a program which could read its data from stdin
and _if_there_is_nothing_at_stdin_ from a file which name is given
as an argument. If there is nothing in stdin and no filename is given as
argument,... (2 Replies)
hello all,
I need to create a password change utility for a database. I need to gather at the command line the username, password and database sid. I have the program currently doing this. What I would like to do is not have the new password appear on the screen when I do my read command.... (2 Replies)
Howdie everyone...
I have a shell script RemoveFiles.sh
Inside this file, it only has two commands as below:
rm -f ../../reportToday/temp/*
rm -f ../../report/*
My problem is that when i execute this script, nothing happened. Files remained unremoved. I don't see any error message as it... (2 Replies)
can you redirect STDIN with command arguments?
I have tried this approach:
# ./script -option <argument1> <argument2> 0<$2
# $2: ambiguous redirect
Is this possible? (4 Replies)
Hi,
Program A: uses pipe()
I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using:
* child
-> dup2(fd, STDOUT_FILENO);
-> execl("/path/PROGRAM B", "PROGRAM B", NULL);
* parent
-> char line;
-> read(fd, line, 100);
Question:
---------... (1 Reply)
Hi,
Program A: uses pipe()
I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using:
* child
-> dup2(fd, STDOUT_FILENO);
-> execl("/path/PROGRAM B", "PROGRAM B", NULL);
* parent
-> char line;
-> read(fd, line, 100);
Question:
---------... (3 Replies)
When a process fork(), the child share the same file descriptors as his father. Thus, they share the same stdin. Quick and dirty exemple below (sorry for the ugly gets() call) :
#include <stdio.h>
#include <unistd.h>
int main()
{
char buf;
if (fork()) { /*parent */
... (1 Reply)
Bonjour,
Mon application en C sous linux tourne en redirigeant stdin vers un fichier.
Exemple; $appli1 <file1.
PB: Je voudrais temporairement redonner la main au user sur le clavier.
Alors je pensais ajouter system("appli2"); dans appli1.
Dans son main() , appli2() fait seulement un... (1 Reply)
Hi,
I has the following command in the script. This command works fine if I execute on command prompt. If I run the script, this is not working as expected (deleting CR).
tr -d "\015" < ${FilePath}/${FileName} > ${FilePath}/${File_Prefix}.csv
I could not figure out whats... (6 Replies)
hi all. and sorry for the random question, but this sparkled a raging flame-war at work and i want more points of view
situation
a router, with linux of some sort,
dhcp client requesting for ip in wan1 (as usual with wan ports)
dhcp server listening in lan1, and assigning ip (as usual... (9 Replies)
Discussion started by: broli
9 Replies
LEARN ABOUT MOJAVE
fpurge
FFLUSH(3) BSD Library Functions Manual FFLUSH(3)NAME
fflush, fpurge -- flush a stream
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h>
int
fflush(FILE *stream);
int
fpurge(FILE *stream);
DESCRIPTION
The function fflush() forces a write of all buffered data for the given output or update stream via the stream's underlying write function.
The open status of the stream is unaffected.
If the stream argument is NULL, fflush() flushes all open output streams.
The function fpurge() erases any input or output buffered in the given stream. For output streams this discards any unwritten output. For
input streams this discards any input read from the underlying object but not yet obtained via getc(3); this includes any text pushed back
via ungetc(3).
RETURN VALUES
Upon successful completion 0 is returned. Otherwise, EOF is returned and the global variable errno is set to indicate the error.
ERRORS
[EBADF] The stream argument is not an open stream, or, in the case of fflush(), not a stream open for writing.
The function fflush() may also fail and set errno for any of the errors specified for the routine write(2).
SEE ALSO write(2), fclose(3), fopen(3), setbuf(3)STANDARDS
The fflush() function conforms to ISO/IEC 9899:1990 (``ISO C90'').
BSD June 4, 1993 BSD