gaspersic/freeCodeCamp
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Proofreading on C file-handling (#33065)

Browse Source
This commit is contained in:
Morgan McLain-Smith
2019-03-23 19:29:22 -04:00
committed by Randell Dawson
parent 29cb844b74
commit c05b6f78ae
1 changed files with 15 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
guide/english/c/file-handling/index.md
View File

@ -29,9 +29,9 @@ FILE *fp;
``` ```
C provides a number of build-in function to perform basic file operation C provides a number of build-in function to perform basic file operation
**fopen()** **-** **create a new file or open a existing file** **fopen()** **-** **creates a new file or open an existing file**
**fclose()** **-** **close a file** **fclose()** **-** **closes a file**
//Most important part is to close the file to restrict any further changes. //Most important part is to close the file to restrict any further changes.
**getc()** **-** **reads a character from a file** **getc()** **-** **reads a character from a file**
@ -43,19 +43,19 @@ C provides a number of build-in function to perform basic file operation
**fprintf()** **-** **writes a set of data to a file** **fprintf()** **-** **writes a set of data to a file**
**getw()** **-** **reads a integer from a file** **getw()** **-** **reads an integer from a file**
**putw()** **-** **writes a integer to a file** **putw()** **-** **writes an integer to a file**
**fseek()** **-** **set the position to desire point** **fseek()** **-** **sets the position to desired point**
**ftell()** **-** **gives current position in the file** **ftell()** **-** **gives current position in the file**
**rewind()** **-** **set the position to the beginning point** **rewind()** **-** **sets the position to the starting point**
### Opening a file ### Opening a file
The **fopen()** function is used to create a file or open a existing file The **fopen()** creates a file or opens an existing file
```c ```c
fp = fopen(const char filename,const char mode); fp = fopen(const char filename,const char mode);
@ -104,7 +104,7 @@ main()
} }
``` ```
Now you might be thinking, "this justs prints text to my screen. How is this file IO?" Now you might be thinking, "This just prints text to my screen. How is this file IO?"
The answer isn't obvious at first, and needs some understanding about the UNIX system. The answer isn't obvious at first, and needs some understanding about the UNIX system.
Under a UNIX system, everything is treated as a file, meaning you can read and write from it. Under a UNIX system, everything is treated as a file, meaning you can read and write from it.
This means that your printer can be abstracted as a file since all you do with a printer is write with it. This means that your printer can be abstracted as a file since all you do with a printer is write with it.
@ -113,12 +113,13 @@ It is also useful to think of these files as streams, since as you'll see later,
So how does this relate to `helloworld` and file IO? So how does this relate to `helloworld` and file IO?
When you call `printf`, you are really just writing to a special file called `stdout`, short for __standard output__. When you call `printf`, you are really just writing to a special file called `stdout`, short for __standard output__.
`stdout` represents, well, the standard output as decided by your shell, which is usually the terminal.
This explains why it printed to your screen. `stdout` is stream used by O's to display the output on the monitor or particularly in your terminal.
There are two other streams (i.e. files) that are available to you with effort, `stdin` and `stderr`. `stdout` represents the standard output as decided by your shell, which is usually the terminal.
`stdin` represents the __standard input__, which your shell usually attaches to the keyboard in terms via keyboard service to console. This explains why it printed to your screen.
`stderr` represents the __standard error__ output, which your shell usually attaches to the terminal but this time to display **errors**.
There are two other streams (i.e. files) that are easily available, `stdin` and `stderr`.
`stdin` represents the __standard input__, which your shell usually attaches to the keyboard.
`stderr` represents the __standard error__ output, which your shell usually attaches to the terminal.
### Rudimentary File IO, or How I Learnt to Lay Pipes ### Rudimentary File IO, or How I Learnt to Lay Pipes
Enough theory, let's get down to business by writing some code! Enough theory, let's get down to business by writing some code!
@ -132,7 +133,7 @@ If you want to append, you can use `>>`. _N.b. these redirection operators are i
./helloworld > hello.txt ./helloworld > hello.txt
``` ```
The contents of `hello.txt` will, not surprisingly, be The contents of `hello.txt` will, unsurprisingly, be
``` ```
Hello, world! Hello, world!