learn_c/intro/ex1_20_detab.c

53 lines
1.0 KiB
C

#include <stdio.h>
#define MAXLINE 1000 /* maximum characters in a line */
#define TABWIDTH 4 /* tab size */
int my_getline(char line[], int maxline);
void detab(char to[], char from[]);
main()
{
int len; /* current line length */
char line[MAXLINE]; /* current input line */
char detab_line[MAXLINE]; /* detabbed line */
while ((len = my_getline(line, MAXLINE)) > 0) {
detab(detab_line, line);
printf("%s", detab_line);
}
return 0;
}
/* my_getline: reads in a line, return the length */
int my_getline(char line[], int lim)
{
int c, i;
for (i = 0; i < lim-1 && (c=getchar()) != EOF && c != '\n'; ++i)
line[i] = c;
if (c == '\n') {
line[i] = c;
++i;
}
line[i] = '\0';
return i;
}
/* detab: replace tab with blanks in line; does not handle the limit */
void detab(char to[], char from[])
{
int i, j, k;
i = j = k = 0;
while ((to[j] = from[i]) != '\0') {
if (to[j] == '\t')
for (k = 0; k < TABWIDTH; ++k, ++j)
to[j] = ' ';
else
++j;
++i;
}
}