Homework & Coursework Questions

int main(        int argc,
                            char *argv[]        )
{
        return(0);
}

int main(int argc, char *argv[]) { return(0); }

$ cat flatc.awk
BEGIN {
        ORS=" " # Records separated by space instead of newline
}

{
        if($0 ~ /^#/)
                printf("\n%s\n", $LINE); # preprocessors statements
        else
        {
                $1=$1;  # awk prints the unmodified line unless you
                        # modify $1..$N somewhere, so $1=$1 flattens

                print;
        }
}

END {
        printf("\n"); # Even one big line must end in \n
}

$ cat popen.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>

int main(int argc, char *argv[])
{
        int status;
        FILE *fp=popen("gunzip", "r");
        char buf[512];

        while(fgets(buf, 512, fp))
        {
                printf("%s", buf);
        }

        if(WEXITSTATUS(status=pclose(fp)))
        {
                printf("gunzip failed with status %d, do rollback\n",
                        WEXITSTATUS(status));
        }
}

$ awk -f flatc.awk < popen.c

#include <stdio.h>

#include <sys/types.h>

#include <sys/wait.h>
 int main(int argc, char *argv[]) { int status; FILE *fp=popen("gunzip", "r"); char buf[512];  while(fgets(buf, 512, fp)) { printf("%s", buf); }  if(WEXITSTATUS(status=pclose(fp))) { printf("gunzip failed with status %d, do rollback\n", WEXITSTATUS(status)); } }

$ awk -f flatc.awk < popen.c |
        # /^#/p means, if a line begins with #, print it.
        # /^#/d means, if a line begins with #, delete it and move to the next line.
        # All the rest reach s/int/flub/g.
        # This way, we can avoid modifying preprocessor statements.
        sed '/^#/p;/^#/d;s/int/flub/g'

#include <stdio.h>

#include <sys/types.h>

#include <sys/wait.h>
 flub main(flub argc, char *argv[]) { flub status; FILE *fp=popen("gunzip", "r"); char buf[512];  while(fgets(buf, 512, fp)) { prflubf("%s", buf); }  if(WEXITSTATUS(status=pclose(fp))) { prflubf("gunzip failed with status %d, do rollback\n", WEXITSTATUS(status)); } }

$

word value(word value, word value, word value....)

# matches and replaces the entire string with nothing.
$ echo "int a(int b, int c)" | sed 's/\([a-z]* [a-z]*\)(\([a-z]* [a-z]*\)\(, [a-z]* [a-z]*\))//g'

# prints first match.
$ echo "int a(int b, int c)" | sed 's/\([a-z]* [a-z]*\)(\([a-z]* [a-z]*\)\(, [a-z]* [a-z]*\)*)/\1/g'
int a
# prints second match
$ echo "int a(int b, int c, int d)" | sed 's/\([a-z]* [a-z]*\)(\([a-z]* [a-z]*\)\(, [a-z]* [a-z]*\)*)/\2/g'
int b
# prints third match
$ echo "int a(int b, int c)" | sed 's/\([a-z]* [a-z]*\)(\([a-z]* [a-z]*\)\(, [a-z]* [a-z]*\)*)/\3/g'
, int d
$

match("string", /regex/, array)