mp-utils/src/cat.c

/* cat.c -- program to concatenate named files and/or stdin onto stdout */
/* version 2 */


#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

#include "support.h"


/* parameters */
enum
    {
    U
    };


/* concat - return a buffer of size new_size containing s1 and s2 concatenated. */
char *concat(char *a1, char *a2, int a1_size, int a2_size)
    {
    char *newbuf;

    newbuf = 0;


    if( !(newbuf = malloc(a1_size+a2_size)))
	{
	throw(MALLOC_FAIL, "concat: couldn't create buffer");
	}

    
    if(a1_size)
	{
	mid_mempcpy(newbuf, a1, a1_size, 0);
	}

    if(a2_size)
	{
	mid_mempcpy(newbuf, a2, a2_size, a1_size);
	}

    
    return(newbuf);
    }


int main(int argc, char **argv)
    {
    int i, c, bufsize, newbufsize;

    char *buf, *newbuf;
    char pars[1] = {0};

    FILE *fd;

    i = c = bufsize = newbufsize = 0;

    buf = newbuf = 0;

    fd = 0;


    /* process our parameters */
    for(; (c = getopt(argc, argv, "u")) != -1; c = 0)
	{
	switch(c)
	    {
	    case 'u': pars[U] = 1;
		break;
	    case ':': 
	    case '?':
	    default: throw(NEEDARG_FAIL, mastrcat(argv[0], " [-u] [file ...]"));
		break;
	    }
	}
    i = optind;


    /* i < argc is obvious; steps through all provided args. */
    /* !argc-optind && !c is a little less so - it allows this loop to run once if the user provides no paths */
    do
	{
	if( !(fd = file_open(argv[i], "r")))
	    {
	    throw(FOPEN_FAIL, mastrcat(argv[0], mastrcat(": could not open file ", argv[i])));
	    }

	if(pars[U])
	    {
	    for(; (c = fgetc(fd)) != EOF; c = 0)
		{
		fputc(c, stdout);
		}
	    }
	else
	    {
	    newbuf = file_read(fd, &newbufsize);
	    buf = concat(buf, newbuf, bufsize, newbufsize);
	    bufsize += newbufsize;
	    free(newbuf);
	    }
	
	i++, newbufsize = 0;
	}
    while((i < argc) || (((argc - optind) == 0) && !c));

    if(!pars[U])
	{
	fwrite(buf, sizeof(char), bufsize, stdout);
	}

    exit(0);
    }