cpmx: added tail command

Author: MiguelVis

cpmx/TAIL.COM

@@ -0,0 +1,207 @@
+/*	tail.c
+
+	Unix-like tail for CP/M.
+
+	Print last lines from files.
+
+	Copyright (c) Miguel I. Garcia Lopez.
+
+	Usage:
+
+	tail [-nNUMBER] [file...]
+
+	Example:
+
+	tail -n6 myletter.doc resume.txt
+	tail calendar.txt
+
+	Revisions:
+
+	07 Sep 2015 : v1.00 : Version for CP/M.
+	07 Sep 2015 : v1.00 : Version for SamaruX as external command.
+	29 May 2016 : v1.01 : Reworked.
+*/
+
+/* Defines for MESCC libraries
+   ---------------------------
+*/
+#define CC_STDIO	// Support for stdin, stdout, stderr
+#define CC_REDIR	// Support for CP/M command line redirection
+
+#define CC_FCX          // Support for user number in filenames.
+
+#define CC_NO_SWITCH    // Exclude support for SWITCH.
+
+/* Standard MESCC library
+   ----------------------
+*/
+#include <mescc.h>
+
+/* Standard MESCC libraries
+   ------------------------
+*/
+#include <conio.h>
+#include <fileio.h>
+#include <printf.h>
+#include <fprintf.h>
+#include <redir.h>
+
+/* Project defs.
+   -------------
+*/
+#define APP_NAME    "tail"
+#define APP_VERSION "v1.01 / 29 May 2016"
+#define APP_COPYRGT "(c) 2015-2016 FloppySoftware"
+#define APP_USAGE   "tail [-nNUMBER] [file...]"
+
+#define MAX_LINES 16
+#define MAX_LNBUF 80
+
+/* The program
+   -----------
+*/
+main(argc, argv)
+int argc, argv[];
+{
+	char *pch, *fn;
+	WORD *linarr; /* char *linarr[] */
+	int lines, i, retcode, argx;
+
+	/* No command line arguments: show usage and exit */
+
+	if(argc == 1)
+	{
+		fprintf(stderr, "%s %s\n\n", APP_NAME, APP_VERSION);
+		fprintf(stderr, "%s\n\n", APP_COPYRGT);
+		fprintf(stderr, "Usage: %s\n", APP_USAGE);
+
+		return 0;
+	}
+
+	/* Default values */
+
+	lines = 10;  /* Print # lines */
+	fn = NULL;   /* Filename */
+
+	/* Parse command line arguments */
+
+	for(i = 1; i < argc; ++i)
+	{
+		pch = argv[i];
+
+		if(*pch == '-')  /* Look for -options */
+		{
+			if(*(++pch) == 'N')
+			{
+				lines = atoi(++pch);
+
+				if(lines < 1 || lines > MAX_LINES)
+					error("Bad # of lines");
+			}
+			else
+				error("Bad option");
+		}
+		else  /* Look for files */
+			break;
+	}
+
+	argx = i;
+
+	/* Get memory for lines */
+
+	if((linarr = malloc(lines + lines)) == NULL)
+		error("No memory");
+
+	for(i = 0; i < lines; ++i)
+	{
+		if((linarr[i] = malloc(MAX_LNBUF)) == NULL)
+			error("No memory");
+	}
+
+	/* Process files */
+
+	if(argx == argc)
+		retcode = do_tail("-", lines, linarr);
+	else
+	{
+		while(argx < argc)
+		{
+			if((retcode = do_tail(argv[argx++], lines, linarr)))
+				break;
+		}
+	}
+
+	/* Success or failure */
+
+	if(retcode)
+		error("Can't open file");
+
+	return 0;
+}
+
+/* Do tail on a file
+   -----------------
+*/
+do_tail(fn, lines, arr)
+char *fn; int lines; WORD *arr; /* char *arr[] */
+{
+	FILE *fp;
+	int i, k, over;
+
+	/* Open the file */
+
+	if(fn[0] == '-' && fn[1] == 0)
+		fp = stdin;
+	else if((fp = fopen(fn, "r")) == NULL)
+		return -1;
+
+	/* Read the file */
+
+	i = over = 0;
+
+	while(fgets(arr[i], MAX_LNBUF, fp) != NULL)
+	{
+		if(++i == lines)
+		{
+			i = 0;
+			over = 1;
+		}
+	}
+
+	/* Print the lines */
+
+	if(!over)
+	{
+		lines = i;
+		i = 0;
+	}
+
+	k = lines;
+
+	while(k--)
+	{
+		putstr(arr[i++]); /* The string already has a \n -- well, maybe not */
+
+		if(over && i == lines)
+			i = 0;
+	}
+
+	/* Close the file */
+
+	if(fp != stdin)
+		fclose(fp);
+
+	/* Success */
+
+	return 0;
+}
+
+/* Print error and exit
+   --------------------
+*/
+error(msg)
+char *msg;
+{
+	fprintf(stderr, "%s: %s.\n", APP_NAME, msg);
+	exit(-1);
+}