How to create a list of word with specific length - c

Question

Im currently writing a C programming to create a list of word with specific length.
For example, I have a string of ten letter
ABCDEFGHIJ
and wanted to create a list of word where the length is 2 that is
AB,BC,CD,DE,EF,FG,GH,HI,IJ.
For now I can only create
AB,CD,EF,GH,IJ
with my coding
#include<stdio.h>
#include<string.h>
int main()
{
/*q=length of query sequence, W=length of substring, t=(q-w)+1*/
char array[5][3],length[3];
int i=1;
FILE *input;
input=fopen("string.txt", "r");
/*stores and prints the data from the string*/
while(fgets(length,3,input))
{
strcpy(array[i],length);
printf(">%d\n%s\n\n",i,array[i]);
i++;
}
return 0;
}
How can I point the array to starts the next word at position from the second letter not the third letter?
Thank you in advance.

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char wmers[115];
int i = 1, j = 2;
FILE *input = NULL;
FILE *output;
if (!(input = fopen("exon11.txt", "r"))) {
// Error
return (EXIT_FAILURE);
}
if (!fgets(wmers,115,input)) {
// Error ?
}
printf(">%d\n%s\n\n",i,wmers);
i++;
output=fopen("2.txt", "w");
fputs(wmers,output);
for(int c = fgetc(input); c != EOF; c = fgetc(input))
{
wmers[0] = wmers[1];
wmers[1] = wmers[2];
wmers[2] = wmers[3];
wmers[3] = wmers[4];
wmers[4] = wmers[5];
wmers[5] = wmers[6];
wmers[6] = wmers[7];
wmers[7] = wmers[8];
wmers[8] = wmers[9];
wmers[9] = wmers[10];
wmers[10] = wmers[11];
wmers[11] = wmers[12];
wmers[12] = wmers[13];
wmers[13] = wmers[14];
wmers[14] = wmers[15];
wmers[15] = wmers[16];
wmers[16] = wmers[17];
wmers[17] = wmers[18];
wmers[18] = wmers[19];
wmers[19] = wmers[20];
wmers[20] = wmers[21];
wmers[21] = wmers[22];
wmers[22] = wmers[23];
wmers[23] = wmers[24];
wmers[24] = wmers[25];
wmers[25] = wmers[26];
wmers[26] = wmers[27];
wmers[27] = wmers[28];
wmers[28] = wmers[29];
wmers[29] = wmers[30];
wmers[30] = wmers[31];
wmers[31] = wmers[32];
wmers[32] = wmers[33];
wmers[33] = wmers[34];
wmers[34] = wmers[35];
wmers[35] = wmers[36];
wmers[36] = wmers[37];
wmers[37] = wmers[38];
wmers[38] = wmers[39];
wmers[39] = wmers[40];
wmers[40] = wmers[41];
wmers[41] = wmers[42];
wmers[42] = wmers[43];
wmers[43] = wmers[44];
wmers[44] = wmers[45];
wmers[45] = wmers[46];
wmers[46] = wmers[47];
wmers[47] = wmers[48];
wmers[48] = wmers[49];
wmers[49] = wmers[50];
wmers[50] = wmers[51];
wmers[51] = wmers[52];
wmers[52] = wmers[53];
wmers[53] = wmers[54];
wmers[54] = wmers[55];
wmers[55] = wmers[56];
wmers[56] = wmers[57];
wmers[57] = wmers[58];
wmers[58] = wmers[59];
wmers[59] = wmers[60];
wmers[60] = wmers[61];
wmers[61] = wmers[62];
wmers[62] = wmers[63];
wmers[63] = wmers[64];
wmers[64] = wmers[65];
wmers[65] = wmers[66];
wmers[66] = wmers[67];
wmers[67] = wmers[68];
wmers[68] = wmers[69];
wmers[69] = wmers[70];
wmers[70] = wmers[71];
wmers[71] = wmers[72];
wmers[72] = wmers[73];
wmers[73] = wmers[74];
wmers[74] = wmers[75];
wmers[75] = wmers[76];
wmers[76] = wmers[77];
wmers[77] = wmers[78];
wmers[78] = wmers[79];
wmers[79] = wmers[80];
wmers[80] = wmers[81];
wmers[81] = wmers[82];
wmers[82] = wmers[83];
wmers[83] = wmers[84];
wmers[84] = wmers[84];
wmers[85] = wmers[86];
wmers[86] = wmers[87];
wmers[87] = wmers[88];
wmers[88] = wmers[89];
wmers[89] = wmers[90];
wmers[90] = wmers[91];
wmers[91] = wmers[92];
wmers[92] = wmers[93];
wmers[93] = wmers[94];
wmers[94] = wmers[95];
wmers[95] = wmers[96];
wmers[96] = wmers[97];
wmers[97] = wmers[98];
wmers[98] = wmers[99];
wmers[99] = wmers[100];
wmers[100] = wmers[101];
wmers[101] = wmers[102];
wmers[102] = wmers[103];
wmers[103] = wmers[104];
wmers[104] = wmers[105];
wmers[105] = wmers[106];
wmers[106] = wmers[107];
wmers[107] = wmers[108];
wmers[108] = wmers[109];
wmers[109] = wmers[110];
wmers[110] = wmers[111];
wmers[111] = wmers[112];
wmers[112] = wmers[113];
wmers[113] = wmers[114];
wmers[114] = c;
printf(">%d\n%s\n\n",j,wmers);
j++;
fputs(wmers,output);
}
return (EXIT_SUCCESS);
}
this is the content of exon11.txt.
CTGCTTGTGAATTTTCTGAGACGGATGTAACAAATACTGAACATCATCAACCCAGTAATAATGATTTGAACACCACTGAGAAGCGTGCAGCTGAGAGGCATCCAGAAAAGTATCAGGGTAGTTCTGTTTCAAACTTGCATGTGGAGCCATGTGGCACAAATACTCATGCCAGCTCATTACAGCATGAGAACAGCAGTTTATTACTCACTAAAGACAGAATGAATGTAGAAAAGGCTGAATTCTGTAATAAAAGCAAACAGCCTGGCTTAGCAAGGAGCCAACATAACAGATGGGCTGGAAGTAAGGAAACATGTAATGATAGGCGGACTCCCAGCACAGAAAAAAAGGTAGATCTGAATGCTGATCCCCTGTGTGAGAGAAAAGAATGGAATAAGCAGAAACTGCCATGCTCAGAGAATCCTAGAGATACTGAAGATGTTCCTTGGATAACACTAAATAGCAGCATTCAGAAAGTTAATGAGTGGTTTTCCAGAAGTGATGAACTGTTAGGTTCTGATGACTCACATGATGGGGAGTCTGAATCAAATGCCAAAGTAGCTGATGTATTGGACGTTCTAAATGAGGTAGATGAATATTCTGGTTCTTCAGAGAAAATAGACTTACTGGCCAGTGATCCTCATGAGGCTTTAATATGTAAAAGTGAAAGAGTTCACTCCAAATCAGTAGAGAGTAATATTGAAGACAAAATATTTGGGAAAACCTATCGGAAGAAGGCAAGCCTCCCCAACTTAAGCCATGTAACTGAAAATCTAATTATAGGAGCATTTGTTACTGAGCCACAGATAATACAAGAGCGTCCCCTCACAAATAAATTAAAGCGTAAAAGGAGACCTACATCAGGCCTTCATCCTGAGGATTTTATCAAGAAAGCAGATTTGGCAGTTCAAAAGACTCCTGAAATGATAAATCAGGGAACTAACCAAACGGAGCAGAATGGTCAAGTGATGAATATTACTAATAGTGGTCATGAGAATAAAACAAAAGGTGATTCTATTCAGAATGAGAAAAATCCTAACCCAATAGAATCACTCGAAAAAGAATCTGCTTTCAAAACGAAAGCTGAACCTATAAGCAGCAGTATAAGCAATATGGAACTCGAATTAAATATCCACAATTCAAAAGCACCTAAAAAGAATAGGCTGAGGAGGAAGTCTTCTACCAGGCATATTCATGCGCTTGAACTAGTAGTCAGTAGAAATCTAAGCCCACCTAATTGTACTGAATTGCAAATTGATAGTTGTTCTAGCAGTGAAGAGATAAAGAAAAAAAAGTACAACCAAATGCCAGTCAGGCACAGCAGAAACCTACAACTCATGGAAGGTAAAGAACCTGCAACTGGAGCCAAGAAGAGTAACAAGCCAAATGAACAGACAAGTAAAAGACATGACAGCGATACTTTCCCAGAGCTGAAGTTAACAAATGCACCTGGTTCTTTTACTAAGTGTTCAAATACCAGTGAACTTAAAGAATTTGTCAATCCTAGCCTTCCAAGAGAAGAAAAAGAAGAGAAACTAGAAACAGTTAAAGTGTCTAATAATGCTGAAGACCCCAAAGATCTCATGTTAAGTGGAGAAAGGGTTTTGCAAACTGAAAGATCTGTAGAGAGTAGCAGTATTTCATTGGTACCTGGTACTGATTATGGCACTCAGGAAAGTATCTCGTTACTGGAAGTTAGCACTCTAGGGAAGGCAAAAACAGAACCAAATAAATGTGTGAGTCAGTGTGCAGCATTTGAAAACCCCAAGGGACTAATTCATGGTTGTTCCAAAGATAATAGAAATGACACAGAAGGCTTTAAGTATCCATTGGGACATGAAGTTAACCACAGTCGGGAAACAAGCATAGAAATGGAAGAAAGTGAACTTGATGCTCAGTATTTGCAGAATACATTCAAGGTTTCAAAGCGCCAGTCATTTGCTCCGTTTTCAAATCCAGGAAATGCAGAAGAGGAATGTGCAACATTCTCTGCCCACTCTGGGTCCTTAAAGAAACAAAGTCCAAAAGTCACTTTTGAATGTGAACAAAAGGAAGAAAATCAAGGAAAGAATGAGTCTAATATCAAGCCTGTACAGACAGTTAATATCACTGCAGGCTTTCCTGTGGTTGGTCAGAAAGATAAGCCAGTTGATAATGCCAAATGTAGTATCAAAGGAGGCTCTAGGTTTTGTCTATCATCTCAGTTCAGAGGCAACGAAACTGGACTCATTACTCCAAATAAACATGGACTTTTACAAAACCCATATCGTATACCACCACTTTTTCCCATCAAGTCATTTGTTAAAACTAAATGTAAGAAAAATCTGCTAGAGGAAAACTTTGAGGAACATTCAATGTCACCTGAAAGAGAAATGGGAAATGAGAACATTCCAAGTACAGTGAGCACAATTAGCCGTAATAACATTAGAGAAAATGTTTTTAAAGAAGCCAGCTCAAGCAATATTAATGAAGTAGGTTCCAGTACTAATGAAGTGGGCTCCAGTATTAATGAAATAGGTTCCAGTGATGAAAACATTCAAGCAGAACTAGGTAGAAACAGAGGGCCAAAATTGAATGCTATGCTTAGATTAGGGGTTTTGCAACCTGAGGTCTATAAACAAAGTCTTCCTGGAAGTAATTGTAAGCATCCTGAAATAAAAAAGCAAGAATATGAAGAAGTAGTTCAGACTGTTAATACAGATTTCTCTCCATATCTGATTTCAGATAACTTAGAACAGCCTATGGGAAGTAGTCATGCATCTCAGGTTTGTTCTGAGACACCTGATGACCTGTTAGATGATGGTGAAATAAAGGAAGATACTAGTTTTGCTGAAAATGACATTAAGGAAAGTTCTGCTGTTTTTAGCAAAAGCGTCCAGAAAGGAGAGCTTAGCAGGAGTCCTAGCCCTTTCACCCATACACATTTGGCTCAGGGTTACCGAAGAGGGGCCAAGAAATTAGAGTCCTCAGAAGAGAACTTATCTAGTGAGGATGAAGAGCTTCCCTGCTTCCAACACTTGTTATTTGGTAAAGTAAACAATATACCTTCTCAGTCTACTAGGCATAGCACCGTTGCTACCGAGTGTCTGTCTAAGAACACAGAGGAGAATTTATTATCATTGAAGAATAGCTTAAATGACTGCAGTAACCAGGTAATATTGGCAAAGGCATCTCAGGAACATCACCTTAGTGAGGAAACAAAATGTTCTGCTAGCTTGTTTTCTTCACAGTGCAGTGAATTGGAAGACTTGACTGCAAATACAAACACCCAGGATCCTTTCTTGATTGGTTCTTCCAAACAAATGAGGCATCAGTCTGAAAGCCAGGGAGTTGGTCTGAGTGACAAGGAATTGGTTTCAGATGATGAAGAAAGAGGAACGGGCTTGGAAGAAAATAATCAAGAAGAGCAAAGCATGGATTCAAACTTAG

Answer 2

Given your question, you have tor ead your file char by char, not 2 char by 2 char :
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char str[3] = "";
FILE *input = NULL;
if (!(input = fopen("string.txt", "r"))) {
// Error
return (EXIT_FAILURE);
}
if (!fgets(str,3,input)) {
// Error ?
}
printf("%s\n", str);
for(int c = fgetc(input); c != EOF; c = fgetc(input)) {
str[0] = str[1];
str[1] = c;
printf("%s\n", str);
}
return (EXIT_SUCCESS);
}
But a better way is to read the whole line (like with getline if you are on Linux) and simply display 2 char by 2 char ...
----------
Okay, so this is not really how SO work, but I'm gonna give you a piece of code.
But before that, some general advice :
Begin by testing your code with little data.
I mean, doing a test with an input of 10 char and a len of 2 is good, doing a test with an input of 3K+ char and a len of 100+ is insane. How do you expect to see if your code is good or bad ?
Cut your code in small function.
And do some "unitary" test on these function. That way, if something failed, you will be able to quickly found the bug without a debugger. If the function to retrieve data work but you end up with a wrong result, the maybe the problem lies when you construct your solution. If the result's construction work but you end up with bad value in your file, then maybe it's the writing function that is at fault. etc etc.
Use str* function.
Doing a manually shift to the left with a string of len 2 is ok, but doing it with a string of 115 is insane ! How many time did you spend on that ?
This is the piece of code that will take a string as an input an do what you want.
Since the array can have any length, the last value of the array is NULL.
It's like a string : to know the len, you search for the particuliar value '\0'. Here, it's not '\0' but rather NULL.
The result array and the string's result are good thanks to calloc that implictly set all array pointeur to NULL and all string content to \0.
That's why strncpy doesn't fail.
// TODO Do the description
char** Magic(const char * const input, size_t len)
{
char **array = NULL;
size_t arraySize = 0;
size_t inputLen = strlen(input);
char **returnFunction = NULL;
// Basic check (assert ?)
if (!len) {
// TODO Error message
goto END_FUNCTION;
}
// Calcul of the array length
if (len <= inputLen) {
arraySize = inputLen - len + 1;
}
// Last array value must be NULL in order to know the array length
++arraySize;
if (!(array = calloc(arraySize, sizeof(*array)))) {
// TODO Error message
goto END_FUNCTION;
}
for (size_t i = 0; i < arraySize - 1; ++i) {
if (!(array[i] = calloc(len + 1, sizeof(*array[i])))) {
// TODO Error message
goto END_FUNCTION;
}
strncpy(array[i], input + i, len);
}
returnFunction = array;
array = NULL;
/* GOTO */END_FUNCTION:
if (array) {
for (size_t i = 0; i < arraySize; ++i) {
free(array[i]);
}
free(array);
}
return (returnFunction);
}
int main(void)
{
char *input = "ABCDEFGIHJ";
size_t inputLen = strlen(input);
char **result = NULL;
for (size_t len = 1; len <= inputLen; ++len) {
// Get result
if (!(result = Magic(input, len))) {
// TODO error log ?
continue;
}
// Display result
printf("result for %zu len : ", len);
for (size_t i = 0; result[i]; ++i) {
printf("%s%s", result[i], result[i + 1] ? ", " : "\n");
}
// Free result
for (size_t i = 0; result[i]; ++i) {
free(result[i]);
}
free(result);
result = NULL;
}
return (EXIT_SUCCESS);
}
What's left up to you is : retrieving the data (and then use it in the "input" argument) and display/writing the data.
For both of these, DO A FUNCTION.
And test. lot of test.
Do not forget to check if there is a failure when calling a function.