You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
50 lines
1.3 KiB
50 lines
1.3 KiB
#include <stdio.h>
|
|
|
|
#define BUFSIZE 1024
|
|
static char buf[BUFSIZE];
|
|
|
|
/* *
|
|
* readline - get a line from stdin
|
|
* @prompt: the string to be written to stdout
|
|
*
|
|
* The readline() function will write the input string @prompt to
|
|
* stdout first. If the @prompt is NULL or the empty string,
|
|
* no prompt is issued.
|
|
*
|
|
* This function will keep on reading characters and saving them to buffer
|
|
* 'buf' until '\n' or '\r' is encountered.
|
|
*
|
|
* Note that, if the length of string that will be read is longer than
|
|
* buffer size, the end of string will be discarded.
|
|
*
|
|
* The readline() function returns the text of the line read. If some errors
|
|
* are happened, NULL is returned. The return value is a global variable,
|
|
* thus it should be copied before it is used.
|
|
* */
|
|
char *
|
|
readline(const char *prompt) {
|
|
if (prompt != NULL) {
|
|
cprintf("%s", prompt);
|
|
}
|
|
int i = 0, c;
|
|
while (1) {
|
|
c = getchar();
|
|
if (c < 0) {
|
|
return NULL;
|
|
}
|
|
else if (c >= ' ' && i < BUFSIZE - 1) {
|
|
cputchar(c);
|
|
buf[i ++] = c;
|
|
}
|
|
else if (c == '\b' && i > 0) {
|
|
cputchar(c);
|
|
i --;
|
|
}
|
|
else if (c == '\n' || c == '\r') {
|
|
cputchar(c);
|
|
buf[i] = '\0';
|
|
return buf;
|
|
}
|
|
}
|
|
}
|
|
|