Format
#include <stdlib.h> char *getenv(const char *varname);
Language Level: ANSI, POSIX, XPG4
getenv searches the list of environment variables for an entry
corresponding to varname.
Return Value
getenv returns a pointer to the environment table entry
containing the current string value of varname. The
return value is NULL if the given variable is not currently
defined or if the system does not support environment variables.
You should copy the string that is returned because it may be written over by a subsequent call to putenv.
Example
In this example, pathvar points to the value
of the PATH environment variable.
#include <stdio.h> #include <stdlib.h>
int main(void)
{
char *pathvar;
pathvar = getenv("PATH");
if (NULL == pathvar)
printf("Environment variable PATH is not defined./n");
else
printf("Path set by environment variable is successfully stored.\n");
return 0;
/************************************************************************
The output should be:
Path set by environment variable PATH is successfully stored. ************************************************************************/ }
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putenv -- Modify Environment Variables
<stdlib.h>