Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Pure C function pointer on printing vowels twice
Top Forums Programming Pure C function pointer on printing vowels twice Post 302997641 by Corona688 on Wednesday 17th of May 2017 04:07:54 PM
Old 05-17-2017
Quote:
Originally Posted by yifangt
What I meant is: Does putchar(c) == EOF have two layers?
First, [COLOR=#170072][FONT=monospace]putchar(c), which will print 'c' out;
Second, evaluate putchar(c) == EOF, which is false because first step is successful.
To get the return value of a function, the function must first be executed, yes.

Quote:
How does 'e' get printed twice in 'Test'? I need each step through the code.
Code:
if(putchar(c) == EOF || putchar(c) == EOF)
if('C' == EOF || putchar(c) == EOF)
if(false || putchar(c) == EOF)
if(putchar(c) == EOF)
if('C' == EOF)
if(false)

Now, if putchar actually DID return eof, it'd ignore the other half. It doesn't need to bother, since true || anything means true. That's why they call || short-circuit evaluation, it can quit early.

Code:
if(putchar(c) == EOF || putchar(c) == EOF)
if(EOF == EOF || putchar(c) == EOF)
if(true || putchar(c) == EOF)
if(true)

 

10 More Discussions You Might Find Interesting

1. Programming

Problem with function which reutrns pointer to a value

i have a function: char *pcCityIdToCountryName(ADMIN_DB_DATA *pstHEader, unit uiCityID) this returns a pointer to CountryName if cityId is given. to retrieve countryname i give: char *CountryName; CountryName = pcCityIdToCountryName(..................); but when i compile it is giving :... (5 Replies)
Discussion started by: jazz
5 Replies

2. Programming

Pure Virtual Function in C++

Dear All, Here I want to know why we put =0 in case of pure virtual function, why not =1, =2 or any thing else Please send me answer any one as soon as possible. (1 Reply)
Discussion started by: krishna_sicsr
1 Replies

3. Programming

How to return void function pointer

Hello all im trying to build function that will return void function pointer what is mean is ( not working ) the main function void * myClass::getFunction(int type){ if(type==1) return &myClass::Test1; if(type==2) return &myClass::Test2; } void myClass::Test1(){... (1 Reply)
Discussion started by: umen
1 Replies

4. Programming

Function pointer to inline function ?

Hi. Problem: I have to parse the payload of a packet. The payload could be in Big Endian Format (network byte order) or little. That depends on a flag present in the header of the packet. Solution: A horrible solution could be to check for that flag everytime I have to read a field in the... (11 Replies)
Discussion started by: emitrax
11 Replies

5. Programming

Function Returning Pointer

Hi guys. how a functions such fdopen, ... can return pointer? are these functions use static memory(variables)? (6 Replies)
Discussion started by: majid.merkava
6 Replies

6. UNIX for Dummies Questions & Answers

Printing pointer address

How can I print the memory address of a pointer using printf (or any other STDOUT functions?). I see in Linux its %p but not in unix, help? thanks (5 Replies)
Discussion started by: perleo
5 Replies

7. Programming

structure pointer array as function parameters

if i create an array of pointers to a structure "struct node" as: struct node *r; and create "n" number of "linked lists" and assign it to the various struct pointers r using some function with a return type as structure pointer as: r=multiplty(.......) /*some parameters*/ is... (2 Replies)
Discussion started by: mscoder
2 Replies

8. Programming

Trivial doubt about C function pointer

Hi, In the below C code, #include <stdio.h> void print() { printf("Hello\n"); } int main() { void (*f)() = (void (*)()) print; f(); (*f)(); } I wonder, how the syntaxes "f()" and "(*f)()" are treated as same without any error? Is this an improvement or ANSI/ISO... (1 Reply)
Discussion started by: royalibrahim
1 Replies

9. UNIX for Dummies Questions & Answers

Counting vowels in string. "Comparison pointer-integer".

I'm trying to write a programme which scans strings to find how many vowels they contain. I get an error saying that I'm trying to compare a pointer and an integer inif(*v == scanme){. How can I overcome this ? Also, the programme seems to scan only the first word of a string e.g.: if I type "abc... (1 Reply)
Discussion started by: fakuse
1 Replies

10. Programming

Segmentation fault when I pass a char pointer to a function in C.

I am passing a char* to the function "reverse" and when I execute it with gdb I get: Program received signal SIGSEGV, Segmentation fault. 0x000000000040083b in reverse (s=0x400b2b "hello") at pointersExample.c:72 72 *q = *p; Attached is the source code. I do not understand why... (9 Replies)
Discussion started by: jose_spain
9 Replies

LEARN ABOUT DEBIAN

set_color

set_color(1)							       fish							      set_color(1)

NAME

       set_color - set_color - set the terminal color

set_color - set the terminal color
   Synopsis
       set_color [-v --version] [-h --help] [-b --background COLOR] [COLOR]

   Description
       Change the foreground and/or background color of the terminal. COLOR is one of black, red, green, brown, yellow, blue, magenta, purple,
       cyan, white and normal.

       o -b, --background Set the background color

       o -c, --print-colors Prints a list of all valid color names

       o -h, --help Display help message and exit

       o -o, --bold Set bold or extra bright mode

       o -u, --underline Set underlined mode

       o -v, --version Display version and exit

       Calling set_color normal will set the terminal color to whatever is the default color of the terminal.

       Some terminals use the --bold escape sequence to switch to a brighter color set. On such terminals, set_color white will result in a grey
       font color, while set_color --bold white will result in a white font color.

       Not all terminal emulators support all these features. This is not a bug in set_color but a missing feature in the terminal emulator.

       set_color uses the terminfo database to look up how to change terminal colors on whatever terminal is in use. Some systems have old and
       incomplete terminfo databases, and may lack color information for terminals that support it. Download and install the latest version of
       ncurses and recompile fish against it in order to fix this issue.

Version 1.23.1							  Sun Jan 8 2012						      set_color(1)
All times are GMT -4. The time now is 10:39 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy