minix/commands/elvis/fmt.c

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2005-04-21 16:53:53 +02:00
/* fmt.c */
/* usage: fmt [-width] [files]...
*
* Fmt rearrages text in order to make each line have roughly the
* same width. Indentation and word spacing is preserved.
*
* The default width is 72 characters, but you can override that via -width.
* If no files are given on the command line, then it reads stdin.
*/
#include <stdio.h>
#ifndef TRUE
# define TRUE 1
# define FALSE 0
#endif
int width = 72; /* the desired line width */
int isblank; /* is the current output line blank? */
int indent; /* width of the indentation */
char ind[512]; /* indentation text */
char word[1024]; /* word buffer */
/* This function displays a usage message and quits */
void usage()
{
fprintf(stderr, "usage: fmt [-width] [files]...\n");
exit(2);
}
/* This function outputs a single word. It takes care of spacing and the
* newlines within a paragraph.
*/
void putword()
{
int i; /* index into word[], or whatever */
int ww; /* width of the word */
int sw; /* width of spacing after word */
static int psw; /* space width of previous word */
static int tab; /* the width of text already written */
/* separate the word and its spacing */
for (ww = 0; word[ww] && word[ww] != ' '; ww++)
{
}
sw = strlen(word) - ww;
word[ww] = '\0';
/* if no spacing (that is, the word was at the end of the line) then
* assume 1 space unless the last char of the word was punctuation
*/
if (sw == 0)
{
sw = 1;
if (word[ww - 1] == '.' || word[ww - 1] == '?' || word[ww - 1] == '!')
sw = 2;
}
/* if this is the first word on the line... */
if (isblank)
{
/* output the indentation first */
fputs(ind, stdout);
tab = indent;
}
else /* text has already been written to this output line */
{
/* will the word fit on this line? */
if (psw + ww + tab <= width)
{
/* yes - so write the previous word's spacing */
for (i = 0; i < psw; i++)
{
putchar(' ');
}
tab += psw;
}
else
{
/* no, so write a newline and the indentation */
putchar('\n');
fputs(ind, stdout);
tab = indent;
}
}
/* write the word itself */
fputs(word, stdout);
tab += ww;
/* remember this word's spacing */
psw = sw;
/* this output line isn't blank anymore. */
isblank = FALSE;
}
/* This function reformats text. */
void fmt(in)
FILE *in; /* the name of the input stream */
{
int ch; /* character from input stream */
int prevch; /* the previous character in the loop */
int i; /* index into ind[] or word[] */
int inword; /* boolean: are we between indent & newline? */
/* for each character in the stream... */
for (indent = -1, isblank = TRUE, inword = FALSE, i = 0, prevch = '\n';
(ch = getc(in)) != EOF;
prevch = ch)
{
/* is this the end of a line? */
if (ch == '\n')
{
/* if end of last word in the input line */
if (inword)
{
/* if it really is a word */
if (i > 0)
{
/* output it */
word[i] = '\0';
putword();
}
}
else /* blank line in input */
{
/* finish the previous paragraph */
if (!isblank)
{
putchar('\n');
isblank = TRUE;
}
/* output a blank line */
putchar('\n');
}
/* continue with next input line... */
indent = -1;
i = 0;
inword = FALSE;
continue;
}
/* if we're expecting indentation now... */
if (indent < 0)
{
/* if this is part of the indentation... */
if (ch == ' ' || ch == '\t')
{
/* remember it */
ind[i++] = ch;
}
else /* end of indentation */
{
/* mark the end of the indentation string */
ind[i] = '\0';
/* calculate the width of the indentation */
for (i = indent = 0; ind[i]; i++)
{
if (ind[i] == '\t')
indent = (indent | 7) + 1;
else
indent++;
}
/* reset the word index */
i = 0;
/* reprocess that last character */
ungetc(ch, in);
}
/* continue in the for-loop */
continue;
}
/* if we get here, we're either in a word or in the space
* after a word.
*/
inword = TRUE;
/* is this the start of a new word? */
if (ch != ' ' && prevch == ' ')
{
/* yes! output the previous word */
word[i] = '\0';
putword();
/* reset `i' to the start of the word[] buffer */
i = 0;
}
word[i++] = ch;
}
/* if necessary, write a final newline */
if (!isblank)
{
putchar('\n');
isblank = TRUE;
}
}
int main(argc, argv)
int argc;
char **argv;
{
FILE *in; /* an input stream */
int error; /* if non-zero, then an error occurred */
int i;
/* handle the -width flag, if given */
if (argc > 1 && argv[1][0] == '-')
{
width = atoi(argv[1] + 1);
if (width <= 0)
{
usage();
}
argc--;
argv++;
}
/* if no filenames given, then process stdin */
if (argc == 1)
{
fmt(stdin);
}
else /* one or more filenames given */
{
for (error = 0, i = 1; i < argc; i++)
{
in = fopen(argv[i], "r");
if (!in)
{
perror(argv[i]);
error = 3;
}
else
{
fmt(in);
fclose(in);
}
}
}
/* exit, possibly indicating an error */
exit(error);
/*NOTREACHED*/
}