Cant read file name when Input through cmd in C ( through args[1] )

Question

This is how I am reading my text files in cmd. It is a constraint.

>gcc -std=c99 myproject.c -o myproject
>myproject<1.txt

What I'm trying to achieve is the file name "1.txt" as a string so that I can read the number for lines in the file. I looked through a bunch of solutions and all of them suggest argv[1] but when I do this:

int main(int args, char*argv[]) {
printf("File: %s\n", argv[1]); }

it prints null.

args gives 1 and argv[0] gives myproject. I don't know what else I could try. All I want to achieve the number of lines in the given input file. Please help. Thanks!

@tkausl Hi, that's how the script is for reading the project. — PhastOfTheFuture, Dec 06 '17 at 15:02
`myproject<1.txt` doesn't pass any arguments to `myproject`. `myproject 1.txt` does. — n. m. could be an AI, Dec 06 '17 at 16:00

DDS · Answer 1 · 2017-12-06T15:44:18.317

2

Using redirection (<) gives the data to the program on the standard input (the program sees the data just as if they were typed in by the keyboard), if you want to pass just the parameter simply delete the redirection.

myproject 1.txt

... if you just want to 'count lines' give a try to the command wc -l, if it's a homework, just check you're dealing with the file in the correct way: Use fscanf, fgetc, fputs, fputc, ... instead of the 'standard input' ones scanf, gets, getc, putc, ...

edited Dec 06 '17 at 15:44

answered Dec 06 '17 at 14:54

DDS

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This doesn't work for me as it just gives the file name but the rest of the program freezes. – PhastOfTheFuture Dec 06 '17 at 15:09
2

May the issue be in the 'rest of the program'? (As you said the code above code 'prints the filename' which is what it has to do) – DDS Dec 06 '17 at 15:19
What is the rest of the program? Using that syntax with the short program you wrote in the OP should work – Tanner Babcock Dec 07 '17 at 03:08

Cant read file name when Input through cmd in C ( through args[1] )

1 Answers1