how to check if a path is actual or symbolic link

I am writing my own shell program. I am currently implementing the cd command using chdir. I want to implement the cd with the below options :

• -P Do not follow symbolic links
• -L Follow symbol开发者_开发技巧ic links (default)

When a given path is entered on the shell, how to figure out if the path is a symbolic link or an absolute path progamatically?

Thanks

Check out the lstat() function , you need to use S_ISLNK on the st_mode field.

if [ -L /path/to/file ]; then
  echo "is a symlink!"
else
  echo "not a symlink! maybe a directory or regular file, or does not exist"
end