Archives week 43 of 2015

linux sh script exception /bin/sh^M:bad interpreter: No such file or directory

reason : This is caused by a different system encoding formats.

resolve : 1.Conversion at windows

        Use UltraEdit or EditPlus

        UltraEdit: File-->Conversions-->DOS-->UNIX

        EditPlus : Edit-->EOL Conversions-->Convert to UNIX Format


        2.Conversion with vi

        >vi filename

        :set ff or :set fileformat

        You can see ...

js call JSON.parse() or eval() to object exception: Uncaught SyntaxError: Unexpected token

Reason : json string include \r\n or \n or \t

resolve : json string .replace(/\r\n/g,"\\r\\n").replace(/\n/g,"\\n").replace(/\t/g,"\\t")

makefile

.SUFFIXES:.c .o    
CC=gcc
SRCS=filerw.c

OBJS=$(SRCS:.c=.o)
EXEC=demo


start: $(OBJS)
    $(CC) -o $(EXEC) $(OBJS)
    @echo '@_@@_@@_@@_@@_@@_@@_@@_@  ok  @_@@_@@_@@_@@_@@_@@_@@_@'

.c.o:
    $(CC) -Wall -g -o $@ -c $<

clean:
    rm -f $(OBJS)

linux c library function to read binary file code

struct person
{
    int id;
    char name[20];
    int age;
    int sex;
    char tel[20];
};


int main(int arg, char *args[])
{
    FILE *p = fopen(args[1], "w");
    if (p == NULL)
    {
        printf("error is %s\n", strerror(errno));
    } else
    {
        printf("success\n");
        struct person man;
        memset(&man, 0 ...

read dir code

int main(int arg, char *args[])
{
    if (arg <2)
        return 0;

    DIR *dp;
    struct dirent *dirp;
    dp = opendir(args[1]);
    if (dp == NULL)
    {
        printf("error is %s\n", strerror(errno));
        return 0;
    }

    while((dirp = readdir(dp)) != NULL)
    {
        printf("%s\n", dirp->d_name);

    }

    closedir(dp);

    return 0;
}

[root@linux ~]# history [n]
[root@linux ~]# history [-c]
[root@linux ~]# history [-raw] histfiles

Parameters：

-n  ：number, meaning ' the n command to list the most recent list ' means!

-c  ：All the history in the current shell delete all content

-a  ：Will be added into the history currently added instruction in histfiles, if not histfiles, then the ...