printf

Writing / Reading Value to an Array in C

I must be going insane. This is incredibly simple so I am apparently overlooking something: Here is my code: int salesarray[20]; scanf("%d",&sales_input); printf("sales_input is %d",sales_input); salesarray[i] = sales_input; printf("salesValue is %d",i,salesarray[i]); Here is what I will see: sales_input is 2salesV...

How can I print a string to the console at specific coordinates in C++?

Hello, I'm trying to print characters in the console at specified coordinates. Up to now I have been using the very ugly printf("\033[%d;%dH%s\n", 2, 2, "str"); But I just had to ask whether C++ had any other way of doing this. The problem is not even that it's ugly, the problem comes up when I try to make myself a prettier function lik...

Using Printf to display on serial port of an ARM microcontroller

I would like to use printf to diplay text on a serial port of an ARM microcontroller. I am unable to do so. Any help is appreciated. My init_serial looks like this void init_serial (void) { PINSEL0 = 0x00050000; /* Enable RXD1 TxD1 */ U1LCR = 0x00000083; /*8 bits, 1 Stop bit */ U1DLL = 0x000000C2; /*9600 Baud Rate @12MHz VPB Clock */ ...

Java: Literal percent sign in printf statement

I'm trying to add an actual percent sign into a printf statement in Java and I'm getting the error: lab1.java:166: illegal escape character System.out.printf("%s\t%s\t%1.2f\%\t%1.2f\%\n",ID,pattern,support,confidence); ^ lab1.java:166: illegal escape character ...

Why does printf not flush after the call unless a newline is in the format string? (in C)

Why does printf not flush after the call unless a newline is in the format string? (in C) Is this POSIX behavior? How might I have printf immediately flush every time? Thanks, Chenz ...

C Programming: Forward variable argument list.

Hi, I'm trying to write a function that accepts a variable number of parameters like printf, does some stuff, then passes the variable list to printf. I'm not sure how to do this, because it seems like it would have to push them onto the stack. Something approximately like this http://pastie.org/694844 #include <stdio.h> #include <st...

In C how do I print filename of file that is redirected as input in shell

$cc a.c $./a.out < inpfilename I want to print inpfilename on stdout. How do I do that ? Thanks for the help in advance... ...

Inconsistent results from printf with long long int?

struct DummyStruct{ unsigned long long std; int type; }; DummyStruct d; d.std = 100; d.type = 10; /// buggy printf, unsigned long long to int conversion is buggy. printf("%d,%d\n",d.std, d.type); // OUTPUT: 0,100 printf("%d,%d\n", d.type, d.std); // OUTPUT: 10,100 printf("%lld,%d\n",d.std, d.type); // OUTPUT: 100,10 ...

In C can a long printf statement be broken up into multiple lines?

I have the following statement: printf("name: %s\targs: %s\tvalue %d\tarraysize %d\n", sp->name, sp->args, sp->value, sp->arraysize); I want to break it up. I tried the following but it doesn't work. printf("name: %s\t args: %s\t value %d\t arraysize %d\n", sp->name, sp->args, sp->value, sp->arraysize); How can I break it up? ...

String formatting expressions (Python)

String formatting expressions: 'This is %d %s example!' % (1, 'nice') String formatting method calls: 'This is {0} {1} example!'.format(1, 'nice') I personally prefer the method calls (second example) for readability but since it is new, there is some chance that one or the other of these may become deprecated over time. Which do y...

Printf and hex values

So, I have a value of type __be16 (2 bytes). In hex, the value is represented as 0x0800 or 2048 in decimal. (16^2 * 8) So, when I printf this; I do this: printf("%04X", value); //__be16 value; //Print a hex value of at least 4 characters, no padding. output: 0008 printf("%i", value); //Print an integer. ou...

Weird result printing pointers as float in C

I know this is wrong and gcc will give you a warning about it, but why does it work (i.e. the numbers are printed correctly, with some rounding difference)? int main() { float *f = (float*) malloc(sizeof(float)); *f = 123.456; printf("%f\n", *f); printf("%f\n", f); return 0; } Edit: Yes, I'm using gcc with a 32-bit mach...

How do you print two places exactly using zero-pad flag in a print statement

if wanted to make a this method print using zero pad how do you do so int month, day; public void printNumeric() { System.out.printf("month +"/" +day +" \n"); // i would like the month if it is 5 to be 05 same thing with the day } ...

Odd rounding problem using the ruby printf-format-specifier

Has anybody got any ideas on this one? When we run: printf("%.0f", 40.5) On a windows box the return is "41" but on our production ubuntu server we're getting "40" ...

Simple formatting question in Java using printf

I have an array of 12 numbers int ary2[] = {3,5,9,11,15,18,22,23,30,31,35,39}; I want to print the numbers out with 2 places for the number and a space between the numbers. Example print out would be : 3 5 9 11 15 18 22 23 30 31 35 39 This is how far I got. for(int i = 0; i < ary2.length; i++) { System.out.printf("%-3s"...

How to format printf statement better so things always line up

I have this printf statement: printf("name: %s\t" "args: %s\t" "value %d\t" "arraysize %d\t" "scope %d\n", sp->name, sp->args, sp->value, sp->arraysize, sp->scope); It's inside a for loop, so it's printing multiple lines for a list of pointers. The proble...

printf modifying a string

Using printf to print "\4unix\5lancs\2ac\2uk\0" I find, instead of a print in the form of ♦unix♣lancs☻ac☻uk, I get garbage (♫ ,►E¦§Qh ↕). I cannot find an explanation for this; I use the following method to tokenise a string: /** * Encode the passed string into a string as defined in the RFC. */ char * encodeString(char *string) { ...

Printf seems to mess the output of a simple C program

Hi there. I have some code to add fractions. #include <stdio.h> #include <stdlib.h> struct frac { int enumerator; int denominator; }; typedef struct frac frac_t; frac_t *Add(frac_t *b1, frac_t *b2) { frac_t rfrac; frac_t *p; p = &rfrac; (*p).enumerator= ((*b1).enumerator* (*b2).denominator) + ((*b2).enumerator* (*b1).d...

How to escape the % sign in C's printf?

How do you escape the % sign when using printf in C? printf("hello\%"); /* not like this */ ...

SIGSEGV, (seemingly) caused by printf

First and foremost, apologies for any cross-posting. Hope I'm not repeating an issue here, but I was unable to find this elsewhere (via Google and Stack Overflow). Here's the gist of the error. If I call printf, sprintf or fprintf anywhere within my code, to display a float, I get a SIGSEGV (EXC_BAD_ACCESS) error. Let me give an example...