Trying to read in from a file

I need a simple way (command line program, if there is a way) to ask for a certain X number of bytes from a file and have it print out the first X characters to standard output.  It's for testing.

Scorpantula
scorpantulaAsked:
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Karl Heinz KremerCommented:
#include <stdio.h>

int main(int argc, char * argv[])
{
    FILE * in;
    int limit;
    int i;

    if (argc != 3)
    {
        fprintf(stderr, "Usage: %s <filename> <byte count>\n", argv[0]);
        exit(-1);
    }

    in = fopen(argv[1], "r");
    if (in == NULL)
    {
        fprintf(stderr, "Cannot open file %s\n", argv[1]);
        exit(-2);
    }

    limit = atoi(argv[2]);

    for (i=0; i < limit; i++)
    {
        putchar(fgetc(in));
    }

    putchar('\n');
    fclose(in);
}

Save this to a file (e.g. test.c), then run "make test", which will create the executable test. Then run the command with two arguments on the command line: The first one is the file name, and the second one the number of characters.

e.g.:

./test test.c 45

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Karl Heinz KremerCommented:
Forgot to say this: The program woks for text files for binary files you need to change the output function, but this depends on what you want to see in the output. (e.g. hex dump, octal values, ...)
mtmikeCommented:
Use head (man head), eg

head -c X FILE

to print out the first X bytes of FILE.
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