tCleaned code formatting, added comments - skroll - scroll a text to stdout
(HTM) git clone git://z3bra.org/skroll
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---
(DIR) commit 2a674f4c077001e6e73e036457eadfec23d5a8e0
(DIR) parent 196ffc4e7bbc0c0893c98d604768f18daa316e38
(HTM) Author: z3bra <willy@mailoo.org>
Date: Mon, 3 Nov 2014 11:19:08 +0100
Cleaned code formatting, added comments
Diffstat:
M skroll.c | 62 +++++++++++++++++--------------
1 file changed, 35 insertions(+), 27 deletions(-)
---
(DIR) diff --git a/skroll.c b/skroll.c
t@@ -32,41 +32,46 @@ static int number = 20; /* number of chars to be shown at the same time */
void skroll (const char *input)
{
int offset, buflen = 0;
- char *buf = NULL;
-
- buflen = strnlen( input, LINE_MAX ) + ( number * 2 ) + 1;
-
- buf = calloc( buflen, sizeof( char ) );
-
- if ( buf == NULL )
+ char *tmp, *buf = NULL;
+
+ /*
+ * allocate a new buffer to hold our input PLUS number spaces at the
+ * start/end of the string
+ */
+ buflen = strnlen(input, LINE_MAX) + (number * 2) + 1;
+ if ((buf = calloc(buflen, sizeof(char))) == NULL)
{
return;
}
/* initialize memory with "spaces" and null-terminate the buffer */
- memset( buf, 0x20, buflen - 1 );
- buf[ buflen - 1 ] = 0;
+ memset(buf, ' ', buflen - 1);
+ buf[buflen - 1] = 0;
/* copy input at place `number` */
- memcpy( buf + number, input, strlen( input ) );
+ memcpy(buf + number, input, strlen(input));
/* remove \n from input string to sanitize output */
- if ( buf[ number + strlen( input ) - 1 ] == '\n' )
+ if ((tmp = strchr(buf, '\n')) != NULL)
{
- buf[ number + strlen( input ) - 1 ] = 0x20;
+ tmp[0] = ' ';
}
/* main loop. will loop forever if run with -l */
- do {
-
- offset = 0;
-
- /* loop executed on each step, after <delay> seconds */
- while ( buf [ offset + number ] != 0 ) {
+ do
+ {
+ /*
+ * each step of the loop will print the buffer, one byte further after each step.
+ * using a carriage return, it makes the text scroll out. Magic..
+ * leading/ending spaces are here to make sure that the text goes from
+ * far right, and goes all the way to far left
+ */
+ for (offset = 0; buf [offset + number] != 0; offset++)
+ {
/* print out `number` characters from the buffer ! */
- putc( '\r', stdout );
- write( 1, buf + offset, number );
+ putc('\r', stdout);
+ write(1, buf + offset, number);
/* if we want a new line, let's do it here */
if (newline) putc('\n', stdout);
t@@ -74,7 +79,6 @@ void skroll (const char *input)
/* flush stdout, and wait for the next step */
fflush(stdout);
usleep(delay*1000000);
- offset++;
}
/* magnolia ? FOWEVA ! */
} while(loop);
t@@ -88,12 +92,13 @@ const char *bufferize (FILE *stream)
char *buf = NULL;
/* allocate space to store the input */
- if ( !(buf = calloc (LINE_MAX + 1, sizeof(char))) ) return NULL;
+ if (!(buf = calloc (LINE_MAX + 1, sizeof(char)))) { return NULL; }
/* buf[LINE_MAX] = 0; */
- memset( buf, 0, LINE_MAX + 1 );
+ memset(buf, 0, LINE_MAX + 1);
/* OMG, NO MORE SPACE LEFT ON DEVICE (or no more input, in fact) */
- if ( feof(stream) || !fgets(buf, LINE_MAX, stream) ) {
+ if (feof(stream) || !fgets(buf, LINE_MAX, stream))
+ {
free (buf);
return NULL;
}
t@@ -106,8 +111,10 @@ int main (int argc, char **argv)
char ch;
const char *buf = NULL;
- while ( (ch = getopt(argc, argv, "hd:ln:r")) != -1 ) {
- switch (ch) {
+ while ((ch = getopt(argc, argv, "hd:ln:r")) != -1)
+ {
+ switch (ch)
+ {
case 'h':
printf("usage: %s [-hlr] [-d delay] [-n number]\n", argv[0]);
exit(0);
t@@ -120,7 +127,8 @@ int main (int argc, char **argv)
}
/* SCROLL ALL THE TEXT! */
- while( (buf = bufferize(stdin)) != NULL ) {
+ while((buf = bufferize(stdin)) != NULL)
+ {
skroll(buf);
}