Commit: 57c866cfbce601fce70bb2107dbee656795a699c - ogatool (git)

oga's tools

Commit MetaInfo

• Révision: 57c866cfbce601fce70bb2107dbee656795a699c (tree)
• l'heure: 2024-10-18 12:50:07
• Auteur: hyperoga <hyperoga@gmai...>
• Commiter: hyperoga

Message de Log

add head.c

Change Summary

• add: head.c

Modification

--- /dev/null
+++ b/head.c
@@ -0,0 +1,122 @@
+/*
+ *   head : ファイルの先頭を指定した行表示する
+ *
+ *     2024/10/18 V0.10 by oga.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+
+#define BUF_SIZE  (4096*10) 
+
+int vf = 0;
+
+/* 
+ *  HeadTail : 指定ファイルの先頭1行と最後1行を読み込む
+ *
+ *    IN : fname   : ファイル名
+ *    OUT: headbuf : はじめの1行(サイズBUF_SIZE以上)
+ */
+int Head(char *fname, int line)
+{
+    FILE   *fp;
+    char   buf[BUF_SIZE];
+    struct stat stbuf;
+    int    filef = 1;   /* 1:file 0:stdin */
+    int    cnt   = 0;
+    int    line2 = 0;   /* abs(line) */
+
+    if (!strcmp(fname, "-")) {
+	filef = 0;
+    } else if (stat(fname, &stbuf) < 0) {
+        perror(fname);
+        return -1;
+    }
+
+    if (filef) {
+        if ((fp = fopen(fname, "r")) == NULL) {
+            perror("fopen");
+            return -2;
+        }
+    } else {
+	fp = stdin;
+    }
+
+    if (line < 0) {
+        line2 = -line;
+    } else {
+        line2 = line;
+    }
+
+    while (fgets(buf, BUF_SIZE, fp)) {
+        if (line < 0) {
+	    /* 先頭n行 */
+            if (cnt < line2) {
+	        printf("%s", buf);
+	    } else {
+	        break;
+	    }
+	} else {
+	    /* 指定行以降を出力 */
+            if (cnt >= line2) {
+	        printf("%s", buf);
+	    }
+	}
+	++cnt;
+    }
+
+    fclose(fp);
+
+    return 0;
+}
+
+void usage()
+{
+    printf("usage: head [{-<n> | +<n>}] [<filename>]\n");
+}
+
+int main(int a, char *b[])
+{
+    char headbuf[BUF_SIZE];
+    char tailbuf[BUF_SIZE];
+    char *fname = NULL;
+    int  i;
+    int  line = -10;      /* default 先頭10行 */
+
+    /* arg check */
+    for (i = 1; i<a; i++) {
+	if (!strncmp(b[i],"-v",2)) {
+	    vf = 1;
+	    continue;
+	}
+	if (b[i][0] == '-' || b[i][0] == '+') {
+	    line = atoi(b[i]);
+	    continue;
+	}
+	if (!strncmp(b[i],"-h",2)) {
+            usage();
+	    exit(1);
+	}
+	fname = b[i];
+    }
+
+    if (line == 0) {
+        usage();
+        exit(1);
+    }
+
+    if (fname == NULL) {
+        /* usage(); */
+        /* exit(1); */
+	fname = "-";
+    }
+
+    Head(fname, line);
+
+    return 0;
+}