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#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#define MAXCMD 256
#define MAXLINE 2048
#define MAXLINELEN 256
char file[MAXLINE][MAXLINELEN];
int linecount = 0;
char command[MAXCMD];
int cmdlen;
int lineno = 0;
void eprint(char *str) {
fprintf(stderr, "%s\n", str);
exit(1);
}
void readcmd() {
printf("%d > ", lineno);
char c;
while ((c = getchar()) != '\n' && cmdlen <= MAXCMD) {
command[cmdlen] = c;
cmdlen++;
}
command[cmdlen] = 0;
}
void emptystr(char *s) {
for (int i = 0; i < strlen(s); i++)
s[i] = 0;
}
void emptycmd() {
emptystr(command);
cmdlen = 0;
}
void readfile(FILE *f) {
int i = 0;
char c;
while ((c = fgetc(f)) != EOF) {
if (c == '\n') {
file[linecount][i] = 0;
linecount++;
i = 0;
} else {
file[linecount][i] = c;
i++;
}
}
}
void printfile(FILE *out, bool numbers) {
for (int i = 0; i < linecount; i++) {
if (!numbers) fprintf(out, "%s\n", file[i]);
else fprintf(out, "%d: %s\n", i, file[i]);
}
}
int readnum() {
if (isdigit(command[0])) {
char num[MAXCMD] = {0};
int i;
for (i = 0; i < cmdlen && isdigit(command[i]); i++) {
num[i] = command[i];
}
num[i] = 0;
return atoi(num);
}
return -1;
}
void deleteline(int n) {
char nfile[MAXLINE][MAXLINELEN];
int nlinecount = 0;
for (int i = 0; i < linecount; i++) {
if (i != n) {
strcpy(nfile[nlinecount], file[i]);
nlinecount++;
}
}
for (int i = 0; i < nlinecount; i++) {
emptystr(file[i]);
strcpy(file[i], nfile[i]);
}
linecount--;
}
void runcmd(char *outpath) {
FILE *f;
int n;
if ((n = readnum()) != -1) {
if (n > linecount) {
printf("?\n");
goto repeat;
}
lineno = n;
}
int i = 0;
repeat:
switch (command[i]) {
case 0:
return;
case 'd':
deleteline(lineno);
break;
case 'P':
printfile(stdout, false);
break;
case 'N':
printfile(stdout, true);
break;
case 'w':
f = fopen(outpath, "w");
printfile(f, false);
fclose(f);
break;
case 'q':
exit(1);
}
i++;
goto repeat;
}
int main(int argc, char **argv) {
FILE *f;
if (argc > 1) {
FILE *f = fopen(argv[1], "r+");
if (f == NULL) eprint("failed to open file");
readfile(f);
fclose(f);
}
else eprint("no file given");
for (;;) {
readcmd();
runcmd(argv[1]);
emptycmd();
}
}
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