steps:

1. Let's say I have a C program inputFileName.c
2. I run inputFileName with input redirection such as ./inputFileName < file

How can I print the name of the file in my C program that I have typed in the terminal as an input redirection file?

CodePudding user response：

The input redirection is a function of the shell. Your inputFileName executable see this as standard input. Depending on the exact operating system, you may be able to use system-specific functions to get the information you want, but there is not a standard means of doing so.

CodePudding user response：

Input redirection can be achieved not only with the '<' symbol, but also with '|'.

program < filename

is equivalent to

cat filename | program

From there, one could go to

cat file1 file2 file3 | program

You begin to see why the initial 'stdin' for an executable cannot and does not have a "filename" associated with it.