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13. How can I manipulate strings of multibyte characters? Say your program sometimes deals with English text (which fits comfortably into 8-bit chars with a bit to spare) and sometimes Japanese text (which needs 16 bits to cover all the…
Read More12. What are multibyte characters? Multibyte characters are another way to make internationalized programs easier to write. Specifically, they help support languages such as Chinese and Japanese that could never fit into eight-bit characters. If your programs will never need…
Read More10. Why shouldn’t I start variable names with underscores? Identifier names beginning with two underscores or an underscore followed by a capital letter are reserved for use by the compiler or standard library functions wherever they appear. In addition, all…
Read More9. What’s a signal? What do I use signals for? A signal is an exceptional condition that occurs during the execution of your program. It might be the result of an error in your program, such as a reference to…
Read More7. What is a “locale”? A locale is a description of certain conventions your program might be expected to follow under certain circumstances. It’s mostly helpful to internationalize your program. If you were going to print an amount of money,…
Read More6. How do I determine whether a character is numeric, alphabetic, and so on? The header file ctype.h defines various functions for determining what class a character belongs to. These consist of the following functions: Function Character…
Read More4. What is the difference between a free-standing and a hosted environment? Not all C programmers write database management systems and word processors. Some write code for embedded systems, such as anti-lock braking systems and intelligent toasters. Embedded systems don’t…
Read More3. How can I write functions that take a variable number of arguments? Use <stdarg.h>. This defines some macros that let your program deal with variable numbers of arguments. There’s no portable way for a C function, with no constraints…
Read More1. Why should I use standard library functions instead of writing my own? The standard library functions have three advantages: they work, they’re efficient, and they’re portable. They work: Your compiler vendor probably got them right. More important, the vendor…
Read More25. How does free() know how much memory to release? There’s no standard way. It can vary from compiler to compiler, even from version to version of the same compiler. free(), malloc(), calloc(), and realloc() are functions; as long as…
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