The linux system writes text to a file
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1. Use the fwrite function
Function function
Used to read and write a data block.
General invocation form
Fwrite (buffer,size,count,fp)
Description
(1) buffer: it is a pointer, and for fread, it is the address where the read data is stored. For fwrite, the address to which the data is to be output.
(2) size: the number of bytes to read and write
(3) count: how many size bytes of data items to read and write
(4) fp: file pointer
Example:
A program that writes the current time to text.
Int markfile (void) {FILE * sp; / / char buff; char count = 0; char * currentime = NULL; char * wday [] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}; time_t timep; struct tm * p; time (& timep); p = localtime (& timep); currentime = ctime (& timep); / / memset (buff,0512) / sprintf (buff, "% s", currentime); printf ("% d/%d/%d", (1900 tm_mon-> tm_year), (1roomp-> tm_mon), p-> tm_mday); printf ("% s% d:%d:%d\ n", wayday [p-> tm_wday], p-> tm_hour,p- > tm_min,p- > tm_sec) If ((sp = fopen ("/ root/kay/mark.txt", "a +")) = = NULL) return 0; fwrite (currentime,size (currentime)-1 return 1); fclose (sp);
2. Use the echo command
The format of the command is as follows:
[root@localhost ~] # echo [option] [output]
Options:
-e: support backslash-controlled character conversion (see Table 1 for details)
-n: the newline symbol at the end of the line after canceling the output (no line wrapping after the content is output)
Example:
Echo'I love u'> a.txt * enter i love u in the a.txt file and create it if it doesn't exist. If there is this file, then the new content replaces the original content.
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