int
main(int argc, char *argv[])
{
int ch, failed;
char *filename;
setlocale(LC_CTYPE, "");
nstops = 1;
tabstops[0] = 8;
while ((ch = getopt(argc, argv, "at:")) != -1) {
switch (ch) {
case 'a': /* Un-expand all spaces, not just leading. */
all = 1;
break;
case 't': /* Specify tab list, implies -a. */
getstops(optarg);
all = 1;
break;
default:
usage();
/*NOTREACHED*/
}
}
argc -= optind;
argv += optind;
failed = 0;
if (argc == 0)
failed |= tabify("stdin");
else {
while ((filename = *argv++) != NULL) {
if (freopen(filename, "r", stdin) == NULL) {
warn("%s", filename);
failed = 1;
} else
failed |= tabify(filename);
}
}
exit(failed != 0);
}
int
main(int argc, char *argv[])
{
int c;
size_t n, column;
setprogname(argv[0]);
//支持旧的语法格式
//expand -20 file.txt
while (argc > 1 &&
argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
getstops(&argv[1][1]);
argc--; argv++;
}
while ((c = getopt (argc, argv, "t:")) != -1) {
switch (c) {
case 't':
getstops(optarg);
break;
case '?':
default:
usage();
}
}
argc -= optind;
argv += optind;
do {
//如果指定的输入是文件，那么将文件打开，重定向到stdin
//这样做的原因是可以和下面处理stdin输入的功能共享代码
if (argc > 0) {
if (freopen(argv[0], "r", stdin) == NULL)
err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
argc--, argv++;
}
column = 0;
while ((c = getchar()) != EOF) {
switch (c) {
case '\t':
//如果没有指定tabstop，则补充输出(8-column)个空格后，检查下一个字符
if (nstops == 0) {
do {
putchar(' ');
column++;
} while (column & 07);
continue;
}
//如果指定了一个tabstop，那么输出最多(tabstop-column)个空格后，检查下一个字符
if (nstops == 1) {
do {
putchar(' ');
column++;
} while (((column - 1) % tabstops[0])
!= (tabstops[0] - 1));
continue;
}
//如果指定了多个tabstop，将指针移到tabstop大于column的位置
for (n = 0; n < nstops; n++){
if (tabstops[n] > column)
break;
}
//如果指定的tabstop都小于column的值，那么输出一个空格后，检查下一个字符
if (n == nstops) {
putchar(' ');
column++;
continue;
}
//否则的话，补充输出(tabstops[n]-column)个空格
while (column < tabstops[n]) {
putchar(' ');
column++;
}
continue;
case '\b':
//遇到Backplace，则行减1，然后输出'\b'
if (column)
column--;
putchar('\b');
continue;
case '\n':
//遇到新的一行，输出行尾，然后重置column为0
putchar(c);
column = 0;
continue;
default:
//如果都不匹配上面的字符，那么输出这个字符，然后自增column值
putchar(c);
column++;
continue;
}
}
} while (argc > 0);
return EXIT_SUCCESS;
}
int
main(int argc, char *argv[])
{
const char *curfile;
wint_t wc;
int c, column;
int n;
int rval;
int width;
setlocale(LC_CTYPE, "");
/* handle obsolete syntax */
while (argc > 1 && argv[1][0] == '-' &&
isdigit((unsigned char)argv[1][1])) {
getstops(&argv[1][1]);
argc--; argv++;
}
while ((c = getopt (argc, argv, "t:")) != -1) {
switch (c) {
case 't':
getstops(optarg);
break;
case '?':
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
rval = 0;
do {
if (argc > 0) {
if (freopen(argv[0], "r", stdin) == NULL) {
warn("%s", argv[0]);
rval = 1;
argc--, argv++;
continue;
}
curfile = argv[0];
argc--, argv++;
} else
curfile = "stdin";
column = 0;
while ((wc = getwchar()) != WEOF) {
switch (wc) {
case '\t':
if (nstops == 0) {
do {
putwchar(' ');
column++;
} while (column & 07);
continue;
}
if (nstops == 1) {
do {
putwchar(' ');
column++;
} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
continue;
}
for (n = 0; n < nstops; n++)
if (tabstops[n] > column)
break;
if (n == nstops) {
putwchar(' ');
column++;
continue;
}
while (column < tabstops[n]) {
putwchar(' ');
column++;
}
continue;
case '\b':
if (column)
column--;
putwchar('\b');
continue;
default:
putwchar(wc);
if ((width = wcwidth(wc)) > 0)
column += width;
continue;
case '\n':
putwchar(wc);
column = 0;
continue;
}
}
if (ferror(stdin)) {
warn("%s", curfile);
rval = 1;
}
} while (argc > 0);
exit(rval);
}
int
main(int argc, char *argv[])
{
int c;
size_t n, column;
setprogname(argv[0]);
/* handle obsolete syntax */
while (argc > 1 &&
argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
getstops(&argv[1][1]);
argc--; argv++;
}
while ((c = getopt (argc, argv, "t:")) != -1) {
switch (c) {
case 't':
getstops(optarg);
break;
case '?':
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
do {
if (argc > 0) {
if (freopen(argv[0], "r", stdin) == NULL)
err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
argc--, argv++;
}
column = 0;
while ((c = getchar()) != EOF) {
switch (c) {
case '\t':
if (nstops == 0) {
do {
putchar(' ');
column++;
} while (column & 07);
continue;
}
if (nstops == 1) {
do {
putchar(' ');
column++;
} while (((column - 1) % tabstops[0])
!= (tabstops[0] - 1));
continue;
}
for (n = 0; n < nstops; n++)
if (tabstops[n] > column)
break;
if (n == nstops) {
putchar(' ');
column++;
continue;
}
while (column < tabstops[n]) {
putchar(' ');
column++;
}
continue;
case '\b':
if (column)
column--;
putchar('\b');
continue;
default:
putchar(c);
column++;
continue;
case '\n':
putchar(c);
column = 0;
continue;
}
}
} while (argc > 0);
return EXIT_SUCCESS;
}