Question

C prgramming (not C++)

## Requirements

You are making an entire program
All this program does is print the environment variables to a file called "env.txt"
Each variable is followed by a newline character

example:
inputs:
    envp/environ = {"E1=2","E2=7",NULL}
outputs:
    env.txt as a string would be "E1=2\nE2=7\n"
example:
inputs:
    envp/environ = {NULL} or NULL
outputs:
    env.txt as a string would be ""

Answer 1

#include <stdio.h>
extern char **environ;
int main(void)
{
int i;
FILE * fp;
fp = fopen ("env.txt","w");
for (i = 0; environ[i] != NULL; i++){
if(environ[i]==NULL){
fp = fopen ("env.txt","w");
fprintf (fp, "");
}
fprintf (fp, "%s\n",environ[i]);
}
fclose (fp);
return 0;
}
you can also get at the environment via environ, even in functions other than main(). The variable environ is unique amongst the global variables defined by POSIX ans is not declared in any header file, so you must write the declaration yourself.

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Please give me a UPVOTE. Thank you :)