Re: Getting a text file rid of all superfluous blank lines

Paul Smith wrote:

On 12/1/05, Les Mikesell <lesmikesell@xxxxxxxxx> wrote:

sed -e 's;^\w*$;;' file-to-clean | grep -v '^$'

Why not use egrep to do it in one pass? Something like:

egrep -v '^\w*$' file-to-clean

Neither of these leave any blank lines.  The idea was
to collapse repeated blank lines or lines containing only
white space to one.

So many ways of solving my problem show that this list is quite creative!

Paul

Do you have gcc installed on your system?

Mike
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#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>

#define LINE_SIZE   1024

typedef enum { ST_ACCEPTING, ST_DISCARDING } State_t;

char    Line[LINE_SIZE];

int     IsBlankLine(const char *Line) {
    while (*Line && isspace(*Line))
        Line++;
    return *Line == '\0';
}

int     main(void) {
    State_t State;

    State = ST_ACCEPTING;
    while (fgets(Line,sizeof Line,stdin)) {
        switch (State) {
            case ST_ACCEPTING:
                fputs(Line,stdout);
                if (IsBlankLine(Line))
                    State = ST_DISCARDING;
                break;
            case ST_DISCARDING:
                if (!IsBlankLine(Line)) {
                    fputs(Line,stdout);
                    State = ST_ACCEPTING;
                }
                break;
            default:
                fputs("can't happen\n",stderr);
                return EXIT_FAILURE;
                break;
        }
    }
    return EXIT_SUCCESS;
}