Hello I am trying to use strdup() for allocation of char pointers within one of my structures, but when compiling gcc complains that strdup() is an implicit function not actually declared? It is within the header file of string.h, but gcc seems to i...

Just as a clarification, alphanumeric characters are ONLY characters between a-z, A-Z and 0-9?

I was wondering what it is meant by indexing non-text files. For example, if we were to index a png file, would the data we would be processing by using fopen() be equivalent to using cat within the terminal? How are words supposed to be indexed if t...

If a command line within the crontab-file contains words after the command name, should it just be ignored, or should it be counted as an error. For example; execute a command at 3AM every day 0 3 daily-backup ERRORWORD? 15 4 d...

I was wondering if commands can show up twice in a crontab-file e.g. 0 3 deep-thought 0 4 deep-thought and are they to be treated as the same for tallying.