Bad out of argv?

I'm using gcc in Ubuntu14. Here is my code: (test.c) #include <stdio.h> int main(int argc, char *argv[]){ int i=0; for(i=1; i <argc;i++) { if (argv[i] = "xx") { printf("I got you!\n"); } printf("%d %s\n",i, argv[i]);

What is the type of the `argv` command line argument in C?

I'm reading a section from C Primer Plus about command-line argument argv and I'm having difficulty understanding this sentence. It says that, The program stores the command line strings in memory and stores the address of each string in an array of

C - Calculator with parameters

I try to create a simple calculator with C. The numbers and operators should be parameters. I already have the main function and a calculate function: main: int main(int argc, char *argv[]){ long result; long number1 = strtol(argv[1], NULL, 10); long

Are the pointers to strings in argv editable?

This question already has an answer here: Is argv[n] writable? 4 answers Recently (Jan 2016, in case the question persists long enough) we had the question Are the strings in argv modifiable?. In the comment section to this answer, we (@2501 and I) a

Why does main (int argc, char * argv []) take two arguments?

This question already has an answer here: Why do we need argc while there is always a null at the end of argv? 4 answers I always thought that argc was required to mark the end of argv but I just learned that argv[argc] == NULL by definition. Am I ri

Problems with rand () in c

I am trying to write a program that simulates a pyjama picking. The main function need to get the amount of pyjamas and the kind of pyjamas as arguments(3 kinds of pyjamas: cheap, regular and expensive). Each pyjama has a name, size and price, the pr

Cleaning an argv program

I have an argv c program, and it reverses the word, and sees if it's a palindrome. I just want to clean up the output and have it print the original input instead of the reversed one, but since it's argv, I can't seem to figure out how to do it. int

How to create a pointer similar to char * argv

The command line pointer char *argv [] used in C language allows operations such as; ptintf ("%c", argv [3][6]); // to print the 7th element of 4th argument printf ("%s", argv [3]); // to print the 4th parsed argument Now I understand

C argv pointer type

I'm confused as to how to use pointers to get this code to work: #include<stdio.h> int main(int argc, char *argv[]){ char* test = argv[1][0]; printf("hello %s\n", test); } Here is the error: incompatible integer to pointer conversion initi

How to write its own function isnumber ()?

I'm new to C and I'm thinking how to write this function myself. I take a parameter from command line, so it is stored in argv array and I want to decide whether it is or isn't number. What is the easiest way to do this? Thank you #include <stdio.h>

Strcpy crash with char * [] (ARGV structure)

This question already has an answer here: Why do I get a segmentation fault when writing to a string initialized with "char *s" but not "char s[]"? 16 answers I have a problem with the c function 'strcpy' that I have not been able to f

WinMain arguments

My issue is that the arguments are only retrieving the first letter in each of the parameters, for this i do not know why.. Could someone elaborate? #include <Windows.h> #include <string> int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hpIns

How to pass sys.argv [n] in a function in Python

I am trying to pass "sys.argv[1]" into a function. #!/usr/bin/env/ python import sys def main(): test(sys.argv[1]) def test(sys.argv[1]): print "Hello " + sys.argv[1] ./arg.py World File "./arg.py", line 5 def test(sys.argv[1

What's wrong with my code? What is argv [1]?

I'm trying to ask the user to type in a string so I will print the length of the string. My code is built succeeded. However, when I entered a word and pressed 'enter', the program keeps running. I had to enter a second word, then the length of the f

C taking arguments from the command prompt as conditions

I'm completely new to C...well sort of. i kind know c++. I'm trying to run a multi-threated program for my assignment, and one of the requirements was to have the user input his commands on the command prompt. Essentially what i'm asking is, how can

Operations chariot double pointer

Assume I have char **argv. First, how can I print out all the strings in argv? I tried the following: char *temp; temp = *argv; // Now points to the first string? while (temp != NULL) { printf("%s ", temp); temp++; } In here, when temp is increm

How to access the options argv / command line in Dart?

And does Dart have a getopt library?Using Options is no longer an option, use: void main(List<String> args) { print(args); } To get executable, use Platform.executable (Platform comes from dart:io) For parsing arguments passed to main, use this cool

How to get the first argument of a program call

I'm making a program in C and this is my code: int main(int argc, char **argv) { int n; char aux[10]; sscanf(argv[1], "%[^-]", aux); n = atoi(aux); } So, if I run the program from command line: my_program -23, I want to get the number "23&q

display original arguments after locating $ 0

When run with arguments a b c d e f g, this script: system("ps ww$$"); { local $0 = "foo"; system("ps ww$$"); } system("ps ww$$"); prints something like: PID TTY STAT TIME COMMAND 16057 pts/5 S+ 0:00 perl /tmp/u a b

How to access argv [] from outside the main () function?

I happen to have several functions which access different arguments of the program through the argv[] array. Right now, those functions are nested inside the main() function because of a language extension the compiler provides to allow such structur

create an array of pointers to files

How would I go about making an array of file pointers in C? I would like to create an array of file pointers to the arguments of main... like a1.txt, a2.txt, etc... So I would run ./prog arg1.txt arg2.txt arg3.txtto have the program use these files.

An integer is required? open()

I have a very simple python script that should scan a text file, which contains lines formatted as id='value' and put them into a dict. the python module is called chval.py and the input file is in.txt. here's the code: import os,sys from os import *