6. Á¶°Ç¹®

Á¶°Ç¹®Àº ¾î¶² ÀÏÀ» ¼öÇàÇϴ°¡ ȤÀº ÇÏÁö ¾Ê´Â°¡ÀÇ ¹®Á¦¸¦ Ç¥ÇöÇϱâ À§ÇÑ ¹æ¹ýÀÌ´Ù.

6.1. ¿äÁ¡¸¸ ¸»ÇÏÀÚ¸é

Á¶°Ç¹®Àº ´Ù¾çÇÑ Çü½ÄÀ¸·Î Ç¥ÇöÇÒ ¼ö ÀÖÁö¸¸ °¡Àå ´ëÁßÀûÀ¸·Î »ç¿ëÇÏ´Â °ÍÀº ´ÙÀ½°ú °°Àº Çü½ÄÀÌ´Ù.

if expression then statement

'statement'´Â 'expression'¿¡ ÇØ´çÇÏ´Â Á¶°ÇÀÌ ÃæÁ·µÇ¾úÀ» ¶§¸¸ ½ÇÇàµÈ´Ù. C¾ð¾î Ã¥ »ç¼­ ù À常 º¸°í ¼Õ ¾È´í ºÐÀ̶ó ÇÒÁö¶óµµ ±¸°æÇØ º¸¼ÌÀ» ¸¸ÇÑ Çü½ÄÀÌ´Ù.

Á¶°Ç¹®ÀÇ Çü½Ä Áß¿¡´Â ´ÙÀ½°ú °°Àº °Íµµ ÀÖ´Ù.

if expression then statement1 else statement2.

ÀÌ°Í ¿ª½Ã ¸¹ÀÌµé º¸½Å ÇüÅÂÀ̰ÚÁö¸¸, 'expression'¿¡ ÇØ´çÇÏ´Â Á¶°ÇÀÌ ÃæÁ·µÇ¸é 'statement1'ÀÌ ½ÇÇàµÇ°í, ±×·¸Áö ¾ÊÀ¸¸é 'statement2'°¡ ½ÇÇàµÇ´Â ¹æ½ÄÀÌ´Ù.

¾Õ¼­ ¸»ÇÑ °Í º¸´Ù Á¶±Ý ´õ ÁøÈ­µÈ ÇüŸ¦ »ìÆìº¸ÀÚ¸é ´ÙÀ½°ú °°´Ù. if expression1 then statement1 else if expression2 then statement2 else statement3. ÀÌ ¹æ½Ä¿¡¼­µµ 'expression1'À» ÃæÁ·Çϸé 'statement1'ÀÌ ½ÇÇàµÈ´Ù´Â Á¡¿¡¼­´Â ¾Õ¼­ »ìÆìº» ¿¹¿Í °°´Ù. ±×·¯³ª 'expression1'ÀÌ ÃæÁ·µÇÁö ¾ÊÀ» °æ¿ì¿¡´Â 'expression2'¶ó´Â »õ·Î¿î Á¶°ÇÀÌ ³ªÅ¸³­´Ù. ¸¸ÀÏ ÀÌ·¸°Ô 'expression2'¿Í ºñ±³ÇÏ¿© Á¶°ÇÀ» ÃæÁ·Çϸé statement2'°¡ ½ÇÇàµÇÁö¸¸ ±×·¸Áö ¾ÊÀ» °æ¿ì¿¡´Â 'statement3'ÀÌ ½ÇÇàµÈ´Ù. ÀÌ °úÁ¤Àº 'else if'¶ó´Â ³à¼®À» ÀÌ¿ëÇϴµ¥, 'else if'¸¦ ¾ó¸¶µçÁö Ãß°¡ÇÏ¿© ´Ù¾çÇÑ ºÐ±â¸¦ ¸¸µé ¼ö ÀÖ´Ù.

°£´ÜÇÑ ¹®¹ý Çü½ÄÀ» º¸µµ·Ï ÇÏÀÚ.

bash¿¡¼­ if¸¦ »ç¿ëÇÒ ¶§¿¡´Â ´ÙÀ½°ú °°Àº Çü½ÄÀ¸·Î ÀÛ¼ºÇÑ´Ù.

if [expression];

then

('expression'ÀÌ ÂüÀ϶§ ½ÇÇàÇÒ ÄÚµå )

fi

6.2. ¿¹Á¦ : ´Ü¼øÇÑ if - then Á¶°Ç¹®

 
#!/bin/bash 
if [ "foo" = "foo" ]; then 
echo expression evaluated as true 
fi 

ÀÌ ÄÚµå´Â if µÚ¿¡ ³ª¿Â Á¶°ÇÀÌ ÂüÀ϶§ 'expression evaluated as true' ¶ó´Â ¹®ÀåÀ» Ãâ·ÂÇÏ´Â ³»¿ëÀÌ´Ù. º¸¸é ¾Ë°ÚÁö¸¸ Á¶°Ç µÚ¿¡´Â 'then'À̶ó°í ÀûÇôÀÖ°í, Á¶°ÇÀÌ ÂüÀ϶§ ½ÇÇàÇÒ ³»¿ëÀ» ÀûÀº µÚ¿¡´Â 'fi'¶ó°í Àû¾î Á¶°Ç¹®ÀÌ ³¡³µÀ½À» ¾Ë·ÁÁØ´Ù.

6.3. ¿¹Á¦ : ´Ü¼øÇÑ if-then-else Á¶°Ç¹®

 
#!/bin/bash 
if [ "foo" = "foo" ]; then 
echo expression evaluated as true 
else 
echo expression evaluated as false 
fi 

6.4. ¿¹Á¦ : º¯¼ö¸¦ »ç¿ëÇÏ¿©

 
#!/bin/bash 
T1="foo" 
T2="bar" 
if [ "$T1" = "$T2" ]; then 
echo expression evaluated as true 
else 
echo expression evaluated as false 
fi