I listened to Jiří's suggestion and started with the outer layers of
the system. This is more suitable for a beginner. As I don't know much
about servers, I started with a simple modification of bdsh's cat and
added an option for numbering all output lines. With this patch you can
do 'cat -n textdemo textdemo' or 'cat --number textdemo textdemo'. This
might be useful when bdsh gets scripting support.
Martin, thank you for a detailed explanation and review. I will have it
in mind when I work on that task in the future, if my knowledge of the
system gets to that level. And also Jakub's comment, as I managed
to cause failed assertions in kernel code from userspace code, which
was strange to me, besides the fact that the solution was too easy, as
Jiří noticed.
Anyway I think I properly tested this patch with all the cat's options.
So, here it is.
=== modified file 'uspace/app/bdsh/cmds/modules/cat/cat.c'
--- uspace/app/bdsh/cmds/modules/cat/cat.c 2013-04-12 09:01:10 +0000
+++ uspace/app/bdsh/cmds/modules/cat/cat.c 2013-07-17 21:10:24 +0000
@@ -62,6 +62,8 @@
static sysarg_t console_rows = 0;
static bool should_quit = false;
static bool dash_represents_stdin = false;
+static unsigned int lineno = 0;
+static bool number = false;
static console_ctrl_t *console = NULL;
@@ -74,6 +76,7 @@
{ "more", no_argument, 0, 'm' },
{ "hex", no_argument, 0, 'x' },
{ "stdin", no_argument, 0, 's' },
+ { "number", no_argument, 0, 'n' },
{ 0, 0, 0, 0 }
};
@@ -94,7 +97,8 @@
" -b, --buffer ## Set the read buffer size to ##\n"
" -m, --more Pause after each screen full\n"
" -x, --hex Print bytes as hex values\n"
- " -s --stdin Treat `-' in file list as standard input\n"
+ " -s, --stdin Treat `-' in file list as standard input\n"
+ " -n, --number Number all output lines\n"
"Currently, %s is under development, some options don't work.\n",
cmdname, cmdname);
}
@@ -153,6 +157,10 @@
static void paged_char(wchar_t c)
{
putchar(c);
+ if (c == '\n' && number == true) {
+ lineno++;
+ printf("%6u ", lineno);
+ }
if (paging_enabled) {
chars_remaining--;
if (c == '\n' || chars_remaining == 0) {
@@ -169,7 +177,7 @@
}
static unsigned int cat_file(const char *fname, size_t blen, bool hex,
- off64_t head, off64_t tail, bool tail_first)
+ off64_t head, off64_t tail, bool tail_first, bool first_file)
{
int fd, bytes = 0, count = 0, reads = 0;
char *buff = NULL;
@@ -178,6 +186,7 @@
off64_t file_size = 0, length = 0;
bool reading_stdin = dash_represents_stdin && (str_cmp(fname, "-") == 0);
+ bool first_line = true;
if (reading_stdin) {
fd = fileno(stdin);
@@ -239,6 +248,12 @@
if (bytes > 0) {
buff[bytes] = '\0';
offset = 0;
+
+ if (number && first_file && first_line) {
+ lineno++;
+ printf("%6u ", lineno);
+ first_line = false;
+ }
for (i = 0; i < bytes && !should_quit; i++) {
if (hex) {
paged_char(hexchars[((uint8_t)buff[i])/16]);
@@ -293,6 +308,7 @@
bool tailFirst = false;
sysarg_t rows, cols;
int rc;
+ bool first_file = false;
/*
* reset global state
@@ -305,11 +321,13 @@
console_rows = 0;
should_quit = false;
console = console_init(stdin, stdout);
+ number = false;
+ lineno = 0;
argc = cli_count_args(argv);
for (c = 0, optind = 0, opt_ind = 0; c != -1;) {
- c = getopt_long(argc, argv, "xhvmH:t:b:s", long_options, &opt_ind);
+ c = getopt_long(argc, argv, "xhvmH:t:b:s:n", long_options, &opt_ind);
switch (c) {
case 'h':
help_cmd_cat(HELP_LONG);
@@ -346,6 +364,9 @@
case 's':
dash_represents_stdin = true;
break;
+ case 'n':
+ number = true;
+ break;
}
}
@@ -372,8 +393,20 @@
newpage();
}
- for (i = optind; argv[i] != NULL && !should_quit; i++)
- ret += cat_file(argv[i], buffer, hex, head, tail, tailFirst);
+ for (i = optind; argv[i] != NULL && !should_quit; i++) {
+ if (i == (unsigned int)optind)
+ first_file = true;
+ ret += cat_file(argv[i], buffer, hex, head, tail, tailFirst, first_file);
+ /* Count the line without the newline character. */
+ if (number && (argv[i+1] != NULL)) {
+ lineno++;
+ printf("\n%6u ", lineno);
+ }
+ first_file = false;
+ }
+
+ if (number)
+ putchar('\n');
if (ret)
return CMD_FAILURE;
_______________________________________________
HelenOS-devel mailing list
[email protected]
http://lists.modry.cz/listinfo/helenos-devel
