Question: I am new in Linux, can anyone tell me which directory the computer search for "ansinist.h"? Below is the syntax:

```
USER@USER-PC /cygdrive/f/Dataset_extract/500ppi-Legacy/SRC/BIN/TXT2NIST
$ make -f makefile.mak
gcc -ansi -O2  -I/include -L/lib -c txt2nist.c
txt2nist.c:15:22: fatal error: ansinist.h: No such file or directory
 #include <ansinist.h>
                      ^
compilation terminated.
makefile.mak:53: recipe for target 'txt2nist.o' failed
make: *** [txt2nist.o] Error 1

```

Answer: 
[This answer](https://askubuntu.com/questions/395490/gcc-cannot-find-ansinist-h-even-though-it-is-there-in-usr-incude-ansinist) could help you. In general case, be sure that you have installed the libraries that you're going to use in your project.
To find the file ansinist.h
sudo find / -name ansinist.h
And please paste your output here but you should be sure you installed all the required libraries first..