getenv() c: The function getenv searches for the environment variable whose name is specified by pointer argument name and returns a C string containing the value of the requested environment variable. The getenv function returns a null pointer, requested environment variable does not exist.
Function prototype of getenv
char *getenv(const char *name);
- name : This is a pointer to a C string containing the name of the requested environment variable.
Return value of getenv
Getenv c: This function returns a null terminated string with the value of the requested environment variable, If it exists otherwise a null pointer.
C program using getenv function
The following program shows the use of getenv function to read environment variable.
#include <stdio.h> #include <stdlib.h> int main () { char *path = getenv("PATH"); if(path!= NULL){ printf("PATH : %s", path); } return(0); }
Output
PATH : /sbin:/usr/sbin:/bin:/usr/bin:/usr/local/bin