name wrote:
On 2004-08-22, Barry Schwarz <sc******@deloz .net> wrote:
<snip?
I'm going to study on this now and prepare for a second revision.
Now that you have thrashed about this on your own, take a look at
the following. The function 'akeyboard()' is not portable, but
does what I want. Note that a -ve linelength parameter allows
ragged right (i.e. wrap) operation.
An exercise for you, if you wish, is to arrange to install the
extra justification blanks from the opposite end of the line on
alternate lines. This is intended to avoid 'rivers' of blanks in
the output.
/* ----- justify.c -----
Filter text file, right justifying by inserting
spaces between words. Words are anything separated
by blanks, tabs, newlines, formfeeds, bell, etc.
The single (optional) parameter is the output line
length, and defaults to 65. Execution without any
input redirections causes a help message.
This is a quick and dirty utility.
Released to public domain by:
<mailto:cb***** ***@worldnet.at t.net>
*/
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#define RHDEFAULT 65
#define RHMIN 20
static int rhcol; /* right hand column limit */
static int ragged; /* No rh justification, 0 init */
/* ------------------- */
/* This is very likely to be non-portable */
/* DOES NOT check fp open for reading */
/* NULL fp is considered a keyboard here! */
static int akeyboard(FILE *fp)
{
#ifndef __TURBOC__
# ifdef __STDC__
/* This dirty operation allows gcc -ansi -pedantic */
extern int fileno(FILE *fp);
extern int isatty(int fn);
# endif
#endif
return ((fp != NULL) && isatty(fileno(f p)));
} /* akeyboard */
/* ------------------- */
static void help(char *phrase1, char *phrase2)
{
if (phrase1) fprintf(stderr, "%s", phrase1);
if (phrase2) fprintf(stderr, "%s", phrase2);
fprintf(stderr, "\n"
"Usage: justify [rightmargin] <infile >outfile\n"
" The default rightmargin is 65\n"
" and values less than 20 are rejected\n"
"\n"
"A large value of rightmargin will effectively\n"
"convert all paragraphs into single lines\n"
"\n"
"A negative rightmargin causes ragged right\n"
"\n"
"A blank line delimits paragraphs\n");
} /* help */
/* ------------------- */
static int initialize(int argc, char *argv[])
{
long rightcol;
char *err;
if (akeyboard(stdi n) || (argc > 2)) {
help(NULL, NULL);
return 0;
}
rhcol = RHDEFAULT;
if (2 == argc) {
rightcol = strtol(argv[1], &err, 10);
if (rightcol < 0) {
rightcol = -rightcol;
ragged = 1;
}
if ((err == argv[1]) || (rightcol < RHMIN)) {
help("Bad argument: ", argv[1]);
return 0;
}
else rhcol = rightcol;
}
return 1;
} /* initialize */
/* ------------------- */
static void cleanup(void)
{
} /* cleanup */
/* ------------------- */
/* =============== =============== ==== */
/* Routines for text input and output */
/* =============== =============== ==== */
static void skipblanks(FILE *f)
{
int ch;
while ( (' ' == (ch = getc(f))) || ('\t' == ch) ||
('\v' == ch) || ('\f' == ch) || ('\a' == ch) )
continue;
ungetc(ch, f);
} /* skipblanks */
/* ------------------- */
/* The file is assumed to hold no control chars */
/* other than \n \t \v \a and \f. A blank line */
/* marks a paragraph ending word */
static int nextword(FILE *f, char *buffer, int max)
{
int i, ch;
skipblanks(f);
if (EOF == (ch = getc(f))) return 0;
/* Detect paragraph endings as \n\n */
if ('\n' == ch) {
skipblanks(f); ch = getc(f);
if ('\n' == ch) { /* paragraph ending */
buffer[0] = buffer[1] = ch; /* wd = "\n\n" */
buffer[2] = '\0';
/* now we have to absorb any more blank lines */
do {
skipblanks(f); ch = getc(f);
} while ('\n' == ch);
ungetc(ch, f);
return 1;
}
}
/* now ch holds the first non-blank. Use all printable */
if (EOF == ch) return 0;
if (!isgraph(ch)) {
fprintf(stderr, "'%c', 0x%x WARN: Invalid character\n",
ch, (unsigned)ch);
}
i = 0;
do {
buffer[i++] = ch;
if (i >= max) { /* truncate over long words */
i--;
break; /* leaving ch for next word */
}
ch = getc(f);
} while (isgraph(ch));
ungetc(ch, f); /* save for next word, may be \n */
buffer[i] = '\0'; /* terminate string */
return 1;
} /* nextword */
/* ------------------- */
static void justify(char *ln, int wdgaps, int xtra, FILE *out)
{
int insert, i;
static int oddln = 0; /* for rt left blank insertion */
char ch;
#ifdef DEBUG
fprintf(out, "%2d %2d ", wdgaps, xtra);
#endif
insert = 0; oddln = !oddln;
if (wdgaps)
while (xtra > wdgaps) {
insert++; xtra -= wdgaps;
}
while ((ch = *ln++)) {
putc(ch, out);
if (' ' == ch) {
if (xtra) {
xtra--;
putc(' ', out);
}
for (i = insert; i; i--) putc(' ', out);
}
}
putc('\n', out);
} /* justify */
/* ------------------- */
static int filter(FILE *in, FILE *out)
{
char *buf;
char *ln;
int wdcount, lnlgh, wdlgh;
char *eop = "\n\n"; /* end of paragraph */
int done, endpar;
if (!(buf = malloc(rhcol+1) )) exit(EXIT_FAILU RE);
if (!(ln = malloc(rhcol+1) )) exit(EXIT_FAILU RE);
done = !nextword(in, buf, rhcol + 1);
endpar = !strcmp(buf, eop);
while (!endpar && !done) {
/* form paragraph */
wdlgh = strlen(buf);
wdcount = 0;
*ln = '\0'; lnlgh = 0;
while ((((lnlgh + wdlgh) < rhcol) || !lnlgh)
&& !done && !endpar) {
/* form a line */
if (lnlgh) ln[lnlgh++] = ' ';
strcpy(ln + lnlgh, buf);
lnlgh += wdlgh;
wdcount++;
done = !nextword(in, buf, rhcol + 1);
endpar = !strcmp(buf, eop);
wdlgh = strlen(buf);
}
/* dump the line, wdcount words */
if (endpar || done) lnlgh = rhcol;
if (ragged) fprintf(out, "%s\n", ln);
else justify(ln, wdcount-1, rhcol-lnlgh, out);
if (endpar) {
fputc('\n', out);
done = !nextword(in, buf, rhcol + 1);
endpar = !strcmp(buf, eop);
}
}
return 0;
} /* filter */
/* ------------------- */
int main(int argc, char *argv[])
{
if (!initialize(ar gc, argv)) return EXIT_FAILURE;
else {
(void)filter(st din, stdout);
cleanup();
}
return 0;
} /* main */
--
fix (vb.): 1. to paper over, obscure, hide from public view; 2.
to work around, in a way that produces unintended consequences
that are worse than the original problem. Usage: "Windows ME
fixes many of the shortcomings of Windows 98 SE". - Hutchison
