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#EASY: problem with strtok parsing a line
worldly patioBOT
wraith salmon
from what I can see on the docs, there's only one delimiter and that's what strtok searches for.
so you'd need to either split up the strtok calls, or just write out an alternate version of strtok yourself.
brazen ravine
you can use multiple delimiters in strtok
wraith salmon
what are you putting into stdin?
sorry, it only showed me examples of it using one
brazen ravine
its a file
wraith salmon
oh yeah it only gets one token per line
brazen ravine
yea
wraith salmon
because you put NULL into the input str at the bottom of the second while loop
shouldn't you put something like strlen(token) + 1 + line into the first argument of the second strtok()?
wraith salmon
wdym lol NULL = no string
it doesn't internally store your string iirc
oh nvm it does
wtf
wraith salmon
no it's in the right place
it could be that it mallocs the token so that the token you're modifying is actually not really the original string
brazen ravine
wat
wraith salmon
when you're lowercasing the token string
it isn't modifying the line string
also i would really just split that into a separate function
brazen ravine
ok
wraith salmon
if it helps at all, this would print out every word like thing:```c
#include <stdio.h>
#include <ctype.h>
int main() {
char str[] = "the fox is very fast";
int start = -1;
int end = 0;
for(int i = 0; str[i]; i ++) {
if(start < 0 && isalnum(str[i]) || str[i] == '')
start = i;
else if(isalnum(str[i]) || str[i] == '') end = i;
else {
printf("%.*s\n", end - start + 1, str + start);
start = -1;
}
}
if(start > -1) printf("%s\n", str + start);
}
in a line
if you want to use something like this, i think it would do the same tihng?
brazen ravine
would this work with an array that im using for my keywords i need to search the file for
wraith salmon
umm do you want me to try to adapt it to your program?
brazen ravine
nah
wraith salmon
but yeah it very much would
do you get how it works? it just keeps up a slice and then it sees if theer's an unfinished word on the second to last line
brazen ravine
ill try to see if i can use some of this
wraith salmon
im pretty sure this is faster than using strtok or wahtever too, and completely threadsafe
brazen ravine
an else if strcmp with the keyword array would work right
brazen ravine
when it prints to stdout some of the words are printed twice & some of them moved onto new lines
wraith salmon
can you post the code?
brazen ravine
while (fgets(line, sizeof(line), stdin))
{
int start = -1;
int end = 0;
for (int i = 0; line[i]; i++)
{
if (start < 0 && isalnum(line[i]) || line[i] == '_')
start = i;
else if (isalnum(line[i]) || line[i] == '_')
end = i;
else
{
printf("%.*s\n", end - start + 1, line + start);
start = -1;
}
}
if (start > -1)
{
printf("%s\n", line + start);
}
}
real torrent
The issue is with the printf("%s\n", line); statement at the end of the while loop. It is printing the original line variable which only contains the first word (the one that was tokenized and potentially modified) and not the entire line with all the modified words. To fix this, you can replace the line variable with a new variable, such as output, and concatenate each modified token to it before printing. Then at the end of each iteration of the while loop, you should reset the output variable to an empty string, so that the next line is printed correctly.
brazen ravine
The issue is with the printf("%s\n", line); statement at the end of the while lo...
i will try that thanks
craggy pivot
try this
while (fgets(line, sizeof(line), stdin))
{
for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++)
{
if (strstr(line, keywords[i]) != NULL)
{
for (j = 0; j < strlen(line); j++)
{
line[j] = tolower(line[j]);
}
break;
}
}
printf("%s", line);
}
doesn't that only replace a keyword once?
craggy pivot
Here is an updated version of the code that will replace multiple keywords at once:
while (fgets(line, sizeof(line), stdin))
{
for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++)
{
char *keyword = keywords[i];
int keyword_len = strlen(keyword);
char *found = strstr(line, keyword);
while (found != NULL)
{
for (j = 0; j < keyword_len; j++)
{
found[j] = tolower(found[j]);
}
found = strstr(found + keyword_len, keyword);
}
}
printf("%s", line);
}
In this version, we are using the strstr() function to check if any of the keywords are present in the line, if they are we are then converting the keyword to lowercase using the tolower() function. We are using while loop to find all occurrence of keyword in the line and replace it with lowercase.
wraith salmon
also, i don't know if that code is very performant
since you're looping through every keyword every line
you could just remove the while fgets though
brazen ravine
Here is an updated version of the code that will replace multiple keywords at on...
if the keyword is present in another word it still lowercases it. i.e if the keyword is "sand" and a word is sandwich, it still gets lowercased. could it be replaced with strcmp
wraith salmon
yeah that's also another downside
wraith salmon
```c
while (fgets(line, sizeof(line), stdin))
{
int start = -1;
...
so for this
ok lemme fix it
craggy pivot
!format
worldly patioBOT
In this version, I have added a check before converting the keyword to lowercase. The check is to verify that the keyword is a standalone word and not a part of another word. We are checking if the keyword is at the start of the line or if the keyword is at the end of the line. If these conditions are satisfied, we are converting the keyword to lowercase.
This way we can avoid partial word matching and also keep it done using strcmp.
while (fgets(line, sizeof(line), stdin)) {
for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
char* keyword = keywords[i];
int keyword_len = strlen(keyword);
char* found = line;
while ((found = strstr(found, keyword)) != NULL) {
int start = found - line;
int end = start + keyword_len;
if ((start == 0 || !isalpha(line[start - 1])) && (!isalpha(line[end]))) {
for (j = 0; j < keyword_len; j++) {
found[j] = tolower(found[j]);
}
}
found += keyword_len;
}
}
printf("%s", line);
}
whiteh4cker
wraith salmon
char* cur;
while ((cur = fgets(line, sizeof(line), stdin)))
{
int start = -1;
int end = 0;
for (int i = 0; cur[i]; i++)
{
if (start < 0 && isalnum(cur[i]) || cur[i] == '_')
start = i;
else if (isalnum(cur[i]) || cur[i] == '_')
end = i;
else
{
printf("%.*s\n", end - start + 1, cur + start);
start = -1;
}
}
if (start > -1)
{
printf("%s\n", cur + start);
}
}
@brazen ravine
brazen ravine
In this version, I have added a check before converting the keyword to lowercase...
this worked
thanks for your help @wraith salmon @craggy pivot @real torrent
craggy pivot
you are welcome
wraith salmon
gl bro
brazen ravine
!solved
worldly patioBOT