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-rw-r--r--Makefile4
-rw-r--r--strstream.c111
2 files changed, 114 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index 8193e1d..9826622 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
CC = gcc
CFLAGS= -O3 -s -mtune=native -Wextra -Wall
-all: count_nucleobases sequence_lengths
+all: count_nucleobases sequence_lengths strstream
count_nucleobases: count_nucleobases.c
$(CC) $(CFLAGS) count_nucleobases.c -o count_nucleobases
@@ -9,6 +9,8 @@ sequence_lengths: sequence_lengths.c
$(CC) $(CFLAGS) sequence_lengths.c -o sequence_lengths
sequence_end_points: sequence_end_points.c
$(CC) $(CFLAGS) sequence_end_points.c -o sequence_end_points
+strstream: strstream.c
+ $(CC) $(CFLAGS) strstream.c -o strstream
clean:
rm -vf count_nucleobases sequence_lengths sequence_end_points
diff --git a/strstream.c b/strstream.c
new file mode 100644
index 0000000..19c7614
--- /dev/null
+++ b/strstream.c
@@ -0,0 +1,111 @@
+// find the positions of any strings in the file pointed by argv[1] in stdin
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+char **load_mers_from_file(FILE *fh, ssize_t *len) {
+ char line[4096];
+
+ size_t realloc_size = 1;
+ *len = 0;
+
+ char **mers = NULL;
+
+ while((fgets(line, 4096, fh)) != NULL) {
+ size_t line_len = strlen(line);
+ if(line_len == 0)
+ continue;
+
+ line[line_len - 1] = '\0';
+
+ mers = realloc(mers, sizeof(char *) * realloc_size);
+ if(mers == NULL) {
+ fprintf(stderr, "could not realloc mers\n");
+ exit(EXIT_FAILURE);
+ }
+
+ char *cpy = malloc(line_len + 1);
+ if(cpy == NULL) {
+ fprintf(stderr, "could not alloc mers\n");
+ exit(EXIT_FAILURE);
+ }
+ strncpy(cpy, line, line_len);
+ mers[*len] = cpy;
+ *len += 1;
+
+ realloc_size++;
+ }
+
+ if(*len != 0)
+ return mers;
+
+ *len = -1;
+ return NULL;
+}
+
+int main(int argc, char **argv){
+
+ char buffer[BUFSIZ] = { 0 };
+ char *buf, *start;
+ ssize_t len = 0;
+ ssize_t mer_len = 0;
+
+ int save_size = 0;
+ int cpy = 0;
+
+ unsigned long long pos = 0;
+ unsigned long long cpy_size = 0;
+
+ int i = 0;
+
+ if(argc != 2) {
+ fprintf(stderr, "usage: strstream merlist.txt\n");
+ exit(EXIT_FAILURE);
+ }
+
+ // load mers
+ FILE *fh = fopen(argv[1], "r");
+ if(fh == NULL) {
+ fprintf(stderr, "could not open %s\n", argv[1]);
+ exit(EXIT_FAILURE);
+ }
+ char **mers = load_mers_from_file(fh, &mer_len);
+ if(mers == NULL) {
+ fprintf(stderr, "could not load mers from %s\n", argv[1]);
+ exit(EXIT_FAILURE);
+ }
+
+ // get max argument length
+ for(i = 0; i < mer_len; i++) {
+ int current_len = strlen(mers[i]);
+ if( current_len > save_size)
+ save_size = current_len;
+ }
+
+ cpy = save_size - 1;
+ cpy_size = BUFSIZ - cpy;
+
+ buf = buffer;
+ start = buf + cpy;
+
+ // copy our first cpy length into the first part of our buffer
+ len = fread(buffer, 1, cpy, stdin);
+ if(len == 0)
+ exit(EXIT_FAILURE);
+
+ // read into "start" (buf + cpy) from tdin
+ while((len = fread(start, 1, cpy_size, stdin)) != 0) {
+ for(i = 0; i < mer_len; i++) {
+ char *p = buffer;
+ while((p = strstr(p, mers[i])) != NULL) {
+ printf("%d %llu\n", i, pos + (p - buffer));
+ p++;
+ }
+ }
+ memcpy(buffer, buffer + len, cpy);
+ pos = pos + len;
+ }
+
+ return 0;
+}