Add LICENSE. Add README. Add overwrite. Add strcmp. Add vis.

This commit is contained in:
Mid Favila 2022-09-06 15:18:34 -04:00
commit 0721d91734
6 changed files with 234 additions and 0 deletions

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README Normal file
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********************************************************************************
* Mid's Extended Utilities *
********************************************************************************
This is a package of supplementary Unix-style utilities. They're meant to be
highly portable and to cover common problems that can't be easily solved with
shell.
-strcmp: Exits with 0 if the provided pair of strings differs. Otherwise, 1.
-vis: Replaces non-printing and non-ASCII characters with octal values.
-unfold: Exactly what it sounds like. unfold will attempt to merge lines
with fewer than the provided number of characters with the next
line, so long as it doesn't cause a word-split.
-overwrite: Reads stdin and writes it to the provided file.

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src/overwrite.c Normal file
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/* overwrite.c -- program to exhaust stdin, then write it to a file */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include "support.h"
int main(int argc, char **argv)
{
int buflen, strlen;
char *buf;
strlen = 0;
buflen = 0;
/* arbitrary */
buflen = 4096;
if(argc == 1)
{
throw(NEEDARG_FAIL, mastrcat(argv[0], " files"));
}
if((buf = malloc(buflen)))
{
int c;
c = 0;
FILE *fp;
for(;((c = getchar()) != EOF);)
{
if(strlen == buflen)
{
buf = realloc(buf, (buflen*=2));
}
buf[strlen++] = c;
}
if(!(fp = fopen(argv[1], "a")))
{
throw(FOPEN_FAIL, argv[1]);
}
for(c = 0; c <= strlen; c++)
{
if(fputc(buf[c], fp) == EOF)
{
throw(WRITE_FAIL, argv[1]);
}
}
/* close the file and exit successfully */
fclose(fp);
}
else
{
throw(MALLOC_FAIL, NULL);
}
return 0;
}

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src/strcmp.c Normal file
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#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include "support.h"
int shortestword(const char* word1, const char* word2)
{
int len = 0;
for(;;)
{
if(!word1[len])
{
return 0;
}
else if(!word2[len++])
{
return 1;
}
}
}
int main(int argc, char **argv)
{
int swl = 0;
/* modify the program to support comparison of an arbitrary number of strings */
if(argc != 3)
{
throw(NEEDARG_FAIL, mastrcat(argv[0], " str1 str2"));
}
if(!shortestword(argv[1], argv[2]))
{
swl = (int) strlen(argv[1]);
}
else
{
swl = (int) strlen(argv[2]);
}
return(strncmp(argv[1], argv[2], swl));
}

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src/support.h Normal file
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#include <iso646.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
enum {
UNKNOWN_FAIL = 1,
MALLOC_FAIL,
NEEDARG_FAIL,
FOPEN_FAIL,
WRITE_FAIL
};
/* arrccat -- function to copy arr2len bytes from arr2 to the arr1len'th position of arr1. returns *newarr, and stores the length */
/* of newarr[] in arr1len (that's why it needs to be a pointer to arr1len and not just a long unsigned integer). */
char *arrccat(char *arr1, char *arr2, size_t *arr1len, size_t arr2len)
{
char *newarr;
unsigned int i, i2;
newarr = malloc(*arr1len+arr2len);
i = i2 = 0;
for(i = 0; i < *arr1len; i++)
{
newarr[i] = arr1[i];
}
for(i2 = 0; i2 < arr2len; i2++, i++)
{
newarr[i] = arr2[i2];
}
*arr1len = *arr1len+arr2len;
return newarr;
}
/* Condition should be one of the above enum'd strings. Info is optional; it can just be NULL when irrelevant. */
void throw(long unsigned int condition, void *info)
{
switch(condition)
{
case UNKNOWN_FAIL: printf("unknown failure\n");
exit(UNKNOWN_FAIL);
case MALLOC_FAIL: printf("malloc failure\n");
exit(MALLOC_FAIL);
case NEEDARG_FAIL: printf("usage: %s\n", (char *) info);
exit(NEEDARG_FAIL);
case FOPEN_FAIL: printf("failed to open: %s\n", (char *) info);
exit(FOPEN_FAIL);
case WRITE_FAIL: printf("failed to write: %s\n", (char *) info);
exit(WRITE_FAIL);
default: printf("You shouldn't be seeing this.\nSomething is very wrong.\n");
exit(-256);
}
}
/* mastrcat -- improved string concat function. returns a pointer to the first element in a buffer containing the strings str1 */
/* and str2 joined end-to-end. */
char *mastrcat(char *str1, char *str2)
{
unsigned long int nbi, stri, nbsize;
char *nbuf;
nbi = stri = 0;
nbsize = (strlen(str1) + strlen(str2));
nbuf = malloc(nbsize);
for(stri = 0; str1[stri] != '\0'; nbi++, stri++)
{
nbuf[nbi] = str1[stri];
}
for(stri = 0; str2[stri] != '\0'; nbi++, stri++)
{
nbuf[nbi] = str2[stri];
}
return nbuf;
}

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src/unfold.c Normal file
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#

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#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "support.h"
int main(int argc, char **argv)
{
int i, c;
FILE *fp;
i = c = 0;
for(;(c = getchar()) != EOF; i++)
{
if(isascii(c) && (c != ' ' && c != '\n' && c != '\t'))
{
printf("%c", c);
}
else
{
printf("%.3o", c);
}
}
return(0);
}