paths must precede expression: `>' in find of execvp c code

Question

#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

int main(void){
    char *argv[6] = {"/home", "-name", "'*.txt'", ">", "all_txt_files.txt", NULL};
    printf("%s\n", argv[2]);    
    execvp("find", argv);
    return 0;
}

If I run the in the bash find /home -name '*.txt' > Jerry.txt that works just fine. But when I run the c code above, it always gives an error /home: paths must precede expression: `>' Looks like nonsense, can someone help? Using WSL 1 in windows 10.

Answer 1

Think of your example from the viewpoint of the find program. When find is started using your execvp, it gets in its argv vector the following parameters:

1. /home
2. -name
3. '*.txt'
4. '>'
5. all_txt_files.txt
6. NULL

When you invoke find from the command line, the shell sets up the redirection and find sees the following parameters:

1. /home
2. -name
3. *.txt
4. NULL

As you can see, the parameters differ in number and content. It is not a surprise that you get a different outcome.

Do do the same in your shell program, you would have either to mimic what the shell is doing.