Integer valueName< unistd.h > symbolic constant 1< stdio.h > file stream 20Standard inputSTDIN_FILENOstdin1Standard outputSTDOUT_FILENOstdout2Standard errorSTDERR_FILENOstderr (echo:: @ ᯤ) Footnotes The Open Group. “The Open Group Base Specifications Issue 7, IEEE Std 1003.1-2008, 2016 Edition”. Retrieved 2017-09-21. ↩ The Open Group. “The Open Group Base Specifications Issue 7, IEEE Std 1003.1-2008, 2016 Edition”. <stdio.h>. Retrieved 2017-09-21. ↩