color.c

/*
 *	Top users/processes display for Unix
 *	Version 3
 *
 *	This program may be freely redistributed,
 *	but this entire comment MUST remain intact.
 */

/*
 * This file handles color definitions and access for augmenting
 * the output with ansi color sequences.
 *
 * The definition of a color setting is as follows, separated by
 * colons:
 *
 * tag=minimum,maximum#code
 *
 * "tag" is the name of the value to display with color.
 *
 * "minimum" and "maximum" are positive integer values defining a range:
 * when the value is within this range it will be shown with the
 * specified color.  A missing value indicates that no check should be
 * made (i.e.: ",25" is n <= 25; "25,50" is 25 <= n <= 50; and "50,"
 * is 50 <= n).
 *
 * "code" is the ansi sequence that defines the color to use with the
 * escape sequence "[m".  Semi-colons are allowed in this string to
 * combine attributes.
 */

#include "os.h"
#include "message.h"
#include "display.h"

typedef struct color_entry
{
	char	   *tag;
	int			min;
	int			max;
	char color;
	struct color_entry *next;
	struct color_entry *tagnext;
}			color_entry;

static color_entry * entries = NULL;

static color_entry * *bytag = NULL;
static char **bytag_names = NULL;
static int	totaltags = 0;
static int	tagcnt = 0;

static char **color_ansi = NULL;
static int	num_color_ansi = 0;
static int	max_color_ansi = 0;

#define COLOR_ANSI_SLOTS 20

static int
color_slot(char *str)
{
	int			i;

	for (i = 0; i < num_color_ansi; i++)
	{
		if (strcmp(color_ansi[i], str) == 0)
		{
			return i;
		}
	}

	/* need a new slot */
	if (num_color_ansi >= max_color_ansi)
	{
		max_color_ansi += COLOR_ANSI_SLOTS;
		color_ansi = (char **) realloc(color_ansi, max_color_ansi * sizeof(char *));
	}
	color_ansi[num_color_ansi] = strdup(str);
	return num_color_ansi++;
}

/*
 * int color_env_parse(char *env)
 *
 * Parse a color specification "env" (such as one found in the environment) and
 * add them to the list of entries.  Always returns 0.	Should only be called
 * once.
 */

int
color_env_parse(char *env)
{
	char	   *p;
	char	   *min;
	char	   *max;
	char	   *str;
	int			len;
	color_entry *ce;

	/* initialization */
	color_ansi = (char **) malloc(COLOR_ANSI_SLOTS * sizeof(char *));
	max_color_ansi = COLOR_ANSI_SLOTS;

	/* color slot 0 is always "0" */
	color_slot("0");

	if (env != NULL)
	{
		p = strtok(env, ":");
		while (p != NULL)
		{
			if ((min = strchr(p, '=')) != NULL &&
				(max = strchr(min, ',')) != NULL &&
				(str = strchr(max, '#')) != NULL)
			{
				ce = (color_entry *) malloc(sizeof(color_entry));
				len = min - p;
				ce->tag = (char *) malloc(len + 1);
				strncpy(ce->tag, p, len);
				ce->tag[len] = '\0';
				ce->min = atoi(++min);
				ce->max = atoi(++max);
				ce->color = color_slot(++str);

				ce->next = entries;
				entries = ce;
			}
			else
			{
				if (min != NULL)
				{
					len = min - p;
				}
				else
				{
					len = strlen(p);
				}
				display_error_message(" %.*s: bad color entry", len, p);
			}
			p = strtok(NULL, ":");
		}
	}
	return 0;
}

/*
 * int color_tag(char *tag)
 *
 * Declare "tag" as a color tag.  Return a tag index to use when testing
 * a valuse against the tests for this tag.  Should not be called before
 * color_env_parse.
 */

int
color_tag(char *tag)
{
	color_entry *entryp;
	color_entry *tp;

	if (tag == NULL || *tag == '\0')
	{
		return -1;
	}

	if (bytag == NULL)
	{
		totaltags = 10;
		bytag = (color_entry * *) malloc(totaltags * sizeof(color_entry *));
		bytag_names = (char **) malloc(totaltags * sizeof(char *));
	}

	if (tagcnt >= totaltags)
	{
		totaltags *= 2;
		bytag = (color_entry * *) realloc(bytag, totaltags * sizeof(color_entry *));
		bytag_names = (char **) realloc(bytag_names, totaltags * sizeof(char *));
	}

	entryp = entries;
	tp = NULL;

	while (entryp != NULL)
	{
		if (strcmp(entryp->tag, tag) == 0)
		{
			entryp->tagnext = tp;
			tp = entryp;
		}
		entryp = entryp->next;
	}

	bytag[tagcnt] = tp;
	bytag_names[tagcnt] = strdup(tag);
	return (tagcnt++);
}

/*
 * int color_test(int tagidx, int value)
 *
 * Test "value" against tests for tag "tagidx", a number previously returned
 * by color_tag.  Return the correct color number to use when highlighting.
 * If there is no match, return 0 (color 0).
 */

int
color_test(int tagidx, int value)
{
	color_entry *ce;

	/* sanity check */
	if (tagidx < 0 || tagidx >= tagcnt)
	{
		return 0;
	}

	ce = bytag[tagidx];

	while (ce != NULL)
	{
		if ((!ce->min || ce->min <= value) &&
			(!ce->max || ce->max >= value))
		{
			return ce->color;
		}
		ce = ce->tagnext;
	}

	return 0;
}

/*
 * char *color_set(int color)
 *
 * Return ANSI string to set the terminal for color number "color".
 */

char *
color_set(int color)
{
	static char v[32];

	v[0] = '\0';
	if (color >=0 && color <num_color_ansi)
	{
		snprintf(v, sizeof(v), "\033[%sm", color_ansi[color]);
	}
	return v;
}

void
color_dump(FILE *f)
{
	color_entry *ep;
	int			i;
	int			col;
	int			len;

	fputs("These color tags are available:", f);
	col = 81;
	for (i = 0; i < tagcnt; i++)
	{
		len = strlen(bytag_names[i]) + 1;
		if (len + col > 79)
		{
			fputs("\n  ", f);
			col = 2;
		}
		fprintf(f, " %s", bytag_names[i]);
		col += len;
	}

	fputs("\n\nTop color settings:\n", f);

	for (i = 0; i < tagcnt; i++)
	{
		ep = bytag[i];
		while (ep != NULL)
		{
			fprintf(f, "   %s (%d-", ep->tag, ep->min);
			if (ep->max != 0)
			{
				fprintf(f, "%d", ep->max);
			}
			fprintf(f, "): ansi color %s, %sSample Text",
					color_ansi[(int) ep->color],
					color_set(ep->color));
			fprintf(f, "%s\n", color_set(0));
			ep = ep->tagnext;
		}
	}
}

void
color_debug(FILE *f)
{
	color_entry *ep;
	int			i;

	printf("color debug dump\n");
	ep = entries;
	while (ep != NULL)
	{
		printf("%s(%d,%d): slot %d, ansi %s, %sSample Text",
			   ep->tag, ep->min, ep->max, ep->color, color_ansi[(int) ep->color],
			   color_set(ep->color));
		printf("%s\n", color_set(0));
		ep = ep->next;
	}

	printf("\ntags:");
	for (i = 0; i < tagcnt; i++)
	{
		printf(" %s", bytag_names[i]);
	}
	printf("\n");
}