getenv
From cppreference.com
| Defined in header
<stdlib.h>
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| const char *getenv( const char *env_var );
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Searches for an environmental variable with name env_var in the host-specified environment list and returns information associated with it. The set of environmental variables and methods of altering it are implementation-defined.
Contents |
[edit] Parameters
| env_var | - | null-terminated character string identifying the name of the environmental variable to look for |
[edit] Return value
character string identifying the value of the environmental variable or NULL if such variable is not found.
[edit] Example
Run this code
#include <stdio.h> #include <stdlib.h> int main(void) { char * env_p; env_p = getenv ("PATH"); if (env_p == NULL) { printf("getenv() failed in file %s at line # %d", __FILE__,__LINE__); exit(1); } printf("PATH = %s\n", env_p); env_p = getenv ("HOME"); printf("HOME = %s\n", env_p); env_p = getenv ("PWD"); printf("PWD = %s\n", env_p); env_p = getenv ("LD_LIBRARY_PATH"); printf("LD_LIBRARY_PATH = %s\n", env_p); env_p = getenv ("LANG"); printf("LANG = %s\n", env_p); env_p = getenv ("LC_ALL"); printf("LC_ALL = %s\n", env_p); env_p = getenv ("TZ"); printf("TZ = %s\n", env_p); return 0; }
Output:
PATH = /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin HOME = /home/sandbox PWD = /tmp/1398126808-1302695176 LD_LIBRARY_PATH = /usr/local/lib LANG = en_US.UTF-8 LC_ALL = C TZ = (null)
[edit] See also
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C++ documentation for getenv
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